feat: add ability to create pre-release tags (#17)

Reviewed-on: #17
Co-authored-by: Timo Behrendt <t.behrendt@t00n.de>
Co-committed-by: Timo Behrendt <t.behrendt@t00n.de>

.gitea/workflows/ci.yaml

@@ -63,3 +63,37 @@ jobs:
           fi
 
           echo "New tag: ${{ steps.increment-tag.outputs.new-tag }}"
+
+  dry-run-prerelease:
+    name: Dry-Run Prerelease
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v5
+        with:
+          fetch-depth: 0
+      - uses: actions/setup-node@v5
+        with:
+          node-version-file: .nvmrc
+      - run: npm ci
+      - name: Create prerelease tag
+        id: prerelease-tag
+        uses: ./
+        with:
+          token: ${{ secrets.GITEA_TOKEN }}
+          prerelease: "true"
+      - name: Print new tag
+        run: |
+          if [ -z "${{ steps.prerelease-tag.outputs.new-tag }}" ]; then
+            echo "No new tag found"
+            exit 1
+          fi
+
+          echo "New tag: ${{ steps.prerelease-tag.outputs.new-tag }}"
+      - name: Verify prerelease tag format
+        run: |
+          if [[ "${{ steps.prerelease-tag.outputs.new-tag }}" =~ -rc-[a-f0-9]{7,}$ ]]; then
+            echo "✓ Prerelease tag format is correct"
+          else
+            echo "✗ Prerelease tag format is incorrect. Expected format: X.Y.Z-rc-<sha>"
+            exit 1
+          fi