We are currently solving the following issue within our repository. Here is the issue text:
--- BEGIN ISSUE ---
rules/participate in project
As you can see in the test, the paricipate_project rule behaves a bit weird for project group members. I think, they should also be allowed to participate. The question is what it is used for.

Cool! The participate_project rule is a bit unexpected, so we should check that out. Like where it is used and what for. But anyway, will merge for now and add an issue.

_Originally posted by @fuzzylogic2000 in https://github.com/liqd/a4-meinberlin/pull/4077#pullrequestreview-837466549_

--- END ISSUE ---

Below are some code segments, each from a relevant file. One or more of these files may contain bugs.
--- BEGIN FILES ---
Path: `meinberlin/apps/projects/rules.py`
Content:
```
1 import rules
2 from rules.predicates import is_superuser
3 
4 from adhocracy4.organisations.predicates import is_initiator
5 from adhocracy4.projects.predicates import is_live
6 from adhocracy4.projects.predicates import is_moderator
7 from adhocracy4.projects.predicates import is_prj_group_member
8 from adhocracy4.projects.predicates import is_project_member
9 from adhocracy4.projects.predicates import is_public
10 from adhocracy4.projects.predicates import is_semipublic
11 
12 rules.remove_perm('a4projects.view_project')
13 rules.add_perm('a4projects.view_project',
14                is_superuser | is_initiator |
15                is_moderator | is_prj_group_member |
16                ((is_public | is_semipublic | is_project_member)
17                 & is_live))
18 
19 rules.set_perm('a4projects.participate_in_project',
20                is_superuser | is_initiator | is_moderator |
21                ((is_public | is_project_member) & is_live))
22
```
--- END FILES ---

Please first localize the bug based on the issue statement, and then generate a patch according to the `git diff` format fenced by three backticks.

Here is an example:

```diff
diff --git a/examples/server_async.py b/examples/server_async.py
--- a/examples/server_async.py
+++ b/examples/server_async.py
@@ -313,4 +313,4 @@
 
 
 if __name__ == "__main__":
-    asyncio.run(run_async_server("."), debug=True)
+    asyncio.run(run_async_server(), debug=True)
diff --git a/examples/server_sync.py b/examples/server_sync.py
--- a/examples/server_sync.py
+++ b/examples/server_sync.py
@@ -313,5 +313,5 @@
 
 
 if __name__ == "__main__":
-    server = run_sync_server(".")
+    server = run_sync_server()
     server.shutdown()

```

diff --git a/meinberlin/apps/projects/rules.py b/meinberlin/apps/projects/rules.py
--- a/meinberlin/apps/projects/rules.py
+++ b/meinberlin/apps/projects/rules.py
@@ -17,5 +17,6 @@
                 & is_live))
 
 rules.set_perm('a4projects.participate_in_project',
-               is_superuser | is_initiator | is_moderator |
+               is_superuser | is_initiator |
+               is_moderator | is_prj_group_member |
                ((is_public | is_project_member) & is_live))

{"golden_diff": "diff --git a/meinberlin/apps/projects/rules.py b/meinberlin/apps/projects/rules.py\n--- a/meinberlin/apps/projects/rules.py\n+++ b/meinberlin/apps/projects/rules.py\n@@ -17,5 +17,6 @@\n                 & is_live))\n \n rules.set_perm('a4projects.participate_in_project',\n-               is_superuser | is_initiator | is_moderator |\n+               is_superuser | is_initiator |\n+               is_moderator | is_prj_group_member |\n                ((is_public | is_project_member) & is_live))\n", "issue": "rules/participate in project\nAs you can see in the test, the paricipate_project rule behaves a bit weird for project group members. I think, they should also be allowed to participate. The question is what it is used for.\r\n\r\nCool! The participate_project rule is a bit unexpected, so we should check that out. Like where it is used and what for. But anyway, will merge for now and add an issue.\r\n\r\n_Originally posted by @fuzzylogic2000 in https://github.com/liqd/a4-meinberlin/pull/4077#pullrequestreview-837466549_\n", "before_files": [{"content": "import rules\nfrom rules.predicates import is_superuser\n\nfrom adhocracy4.organisations.predicates import is_initiator\nfrom adhocracy4.projects.predicates import is_live\nfrom adhocracy4.projects.predicates import is_moderator\nfrom adhocracy4.projects.predicates import is_prj_group_member\nfrom adhocracy4.projects.predicates import is_project_member\nfrom adhocracy4.projects.predicates import is_public\nfrom adhocracy4.projects.predicates import is_semipublic\n\nrules.remove_perm('a4projects.view_project')\nrules.add_perm('a4projects.view_project',\n               is_superuser | is_initiator |\n               is_moderator | is_prj_group_member |\n               ((is_public | is_semipublic | is_project_member)\n                & is_live))\n\nrules.set_perm('a4projects.participate_in_project',\n               is_superuser | is_initiator | is_moderator |\n               ((is_public | is_project_member) & is_live))\n", "path": "meinberlin/apps/projects/rules.py"}], "after_files": [{"content": "import rules\nfrom rules.predicates import is_superuser\n\nfrom adhocracy4.organisations.predicates import is_initiator\nfrom adhocracy4.projects.predicates import is_live\nfrom adhocracy4.projects.predicates import is_moderator\nfrom adhocracy4.projects.predicates import is_prj_group_member\nfrom adhocracy4.projects.predicates import is_project_member\nfrom adhocracy4.projects.predicates import is_public\nfrom adhocracy4.projects.predicates import is_semipublic\n\nrules.remove_perm('a4projects.view_project')\nrules.add_perm('a4projects.view_project',\n               is_superuser | is_initiator |\n               is_moderator | is_prj_group_member |\n               ((is_public | is_semipublic | is_project_member)\n                & is_live))\n\nrules.set_perm('a4projects.participate_in_project',\n               is_superuser | is_initiator |\n               is_moderator | is_prj_group_member |\n               ((is_public | is_project_member) & is_live))\n", "path": "meinberlin/apps/projects/rules.py"}]}