ci: add a fake version of tag.yml workflow

This fake version of the tag.yml workflow is used to verify as much as
possible that the changes in tag.yml are going to work as expected.

.github/workflows/faketag.yml

@@ -0,0 +1,94 @@
+name: Fake Application Release
+
+# This is a simplified copy of tag.yml, only there for testing during PR.
+# It does not create any release or upload any assets: publishing steps are replaced
+# by a call to `ls` showing which assets are available.
+
+on:
+  pull_request:
+
+jobs:
+  build_release_assets:
+    uses: .github/workflows/build_release_assets.yml
+    secrets: inherit
+
+  push_to_pypi:
+    needs: build_release_assets
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+      - name: Set up Python
+        uses: actions/setup-python@v5
+        with:
+          python-version: '3.x'
+
+      - name: Download packages
+        uses: actions/download-artifact@v4
+        with:
+          name: packages
+
+      - name: List downloaded artifacts
+        run: |
+          ls packages
+          ls dist
+
+  release:
+    runs-on: ubuntu-latest
+    needs: build_release_assets
+    continue-on-error: true
+
+    # This is required for `gh release create` to work
+    permissions:
+      contents: write
+
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+        with:
+          fetch-depth: 0
+
+      - name: Read info
+        id: tags
+        shell: bash
+        run: |
+          echo "tag=${GITHUB_REF/refs\/tags\//}" >> $GITHUB_OUTPUT
+
+      - name: Download packages
+        uses: actions/download-artifact@v4
+        with:
+          name: packages
+
+      - name: Download standalone binaries
+        uses: actions/download-artifact@v4
+        with:
+          pattern: standalone-binaries-*
+          path: standalone-binaries
+          merge-multiple: true
+
+      - name: List downloaded artifacts
+        run: |
+          ls \
+            packages/ggshield-*.pyz \
+            packages/ggshield_*.deb \
+            packages/ggshield-*.rpm \
+            standalone-binaries/ggshield-*.pkg
+
+  push_to_cloudsmith:
+    needs: build_release_assets
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+
+      - name: Download packages
+        uses: actions/download-artifact@v4
+        with:
+          name: packages
+
+      - name: Install Cloudsmith CLI
+        run: pip install cloudsmith-cli
+
+      - name: List downloaded artifacts
+        run: |
+          ls packages
+          ls dist