ci : zip windows artifacts for release uploading (#3124)

This commit adds steps to the windows jobs to zip and upload
artifacts produced.

The motivation for this is that currently the artifacts are not zipped
which means that will not be picked up by the release job and hence not
be included in github releases.

Resolves: https://github.com/ggml-org/whisper.cpp/issues/3119

.github/workflows/build.yml

@@ -604,12 +604,19 @@ jobs:
           name: ggml_cpu_${{ matrix.arch }}.dll
           path: build/bin/${{ matrix.build }}/ggml-cpu.dll
 
+      - name: Pack bin artifacts
+        shell: pwsh
+        run: |
+              Compress-Archive -Path "build/bin/${{ matrix.build }}" -DestinationPath "whisper-bin-${{ matrix.arch }}.zip"
+
       - name: Upload binaries
-        if: matrix.sdl2 == 'ON'
+        if: matrix.sdl2 == 'ON' && ${{ (github.event_name == 'push' && github.ref == 'refs/heads/master') ||
+                github.event.inputs.create_release == 'true' ||
+                github.event.inputs.pre_release_tag != '' }}
         uses: actions/upload-artifact@v4
         with:
-          name: whisper-bin-${{ matrix.arch }}
-          path: build/bin/${{ matrix.build }}
+          name: whisper-bin-${{ matrix.arch }}.zip
+          path: whisper-bin-${{ matrix.arch }}.zip
 
   windows-blas:
     if: ${{ github.event_name == 'push' || github.event_name == 'pull_request' ||
@@ -679,12 +686,19 @@ jobs:
         if: matrix.sdl2 == 'ON'
         run: copy "$env:SDL2_DIR/../lib/${{ matrix.s2arc }}/SDL2.dll" build/bin/${{ matrix.build }}
 
+      - name: Pack bin artifacts
+        shell: pwsh
+        run: |
+              Compress-Archive -Path "build/bin/${{ matrix.build }}" -DestinationPath "whisper-blas-bin-${{ matrix.arch }}.zip"
+
       - name: Upload binaries
-        if: matrix.blas == 'ON' && matrix.sdl2 == 'ON'
+        if: matrix.blas == 'ON' && matrix.sdl2 == 'ON' && ${{ (github.event_name == 'push' && github.ref == 'refs/heads/master') ||
+                github.event.inputs.create_release == 'true' ||
+                github.event.inputs.pre_release_tag != '' }}
         uses: actions/upload-artifact@v4
         with:
-          name: whisper-blas-bin-${{ matrix.arch }}
-          path: build/bin/${{ matrix.build }}
+          name: whisper-blas-bin-${{ matrix.arch }}.zip
+          path: whisper-blas-bin-${{ matrix.arch }}.zip
 
   windows-cublas:
     if: ${{ github.event_name == 'push' || github.event_name == 'pull_request' ||
@@ -874,11 +888,19 @@ jobs:
         if: matrix.sdl2 == 'ON'
         run: copy "$env:SDL2_DIR/../lib/${{ matrix.arch }}/SDL2.dll" build/bin/${{ matrix.build }}
 
+      - name: Pack bin artifacts
+        shell: pwsh
+        run: |
+              Compress-Archive -Path "build/bin/${{ matrix.build }}" -DestinationPath "whisper-cublas-${{ matrix.cuda-toolkit }}-bin-${{ matrix.arch }}.zip"
+
       - name: Upload binaries
+        if: ${{ (github.event_name == 'push' && github.ref == 'refs/heads/master') ||
+                github.event.inputs.create_release == 'true' ||
+                github.event.inputs.pre_release_tag != '' }}
         uses: actions/upload-artifact@v4
         with:
-          name: whisper-cublas-${{ matrix.cuda-toolkit }}-bin-${{ matrix.arch }}
-          path: build/bin/${{ matrix.build }}
+          name: whisper-cublas-${{ matrix.cuda-toolkit }}-bin-${{ matrix.arch }}.zip
+          path: whisper-cublas-${{ matrix.cuda-toolkit }}-bin-${{ matrix.arch }}.zip
 
   emscripten:
     if: ${{ github.event_name == 'push' || github.event_name == 'pull_request' ||
@@ -1140,6 +1162,9 @@ jobs:
     needs:
       - determine-tag
       - ios-xcode-build
+      - windows
+      - windows-blas
+      - windows-cublas
 
     steps:
       - name: Clone