Make release asset upload idempotent

.gitea/workflows/build.yml

@@ -10,6 +10,8 @@ on:
 jobs:
   build:
     runs-on: ubuntu-latest
+    env:
+      MRTRUST_VERSION: 0.1.3
 
     steps:
       - name: Checkout
@@ -24,7 +26,6 @@ jobs:
         shell: bash
         run: |
           set -euo pipefail
-          version="0.1.3"
           dotnet publish src/MrTrustLauncher.csproj \
             --configuration Release \
             --runtime win-x64 \
@@ -38,7 +39,7 @@ jobs:
         shell: bash
         run: |
           set -euo pipefail
-          version="0.1.3"
+          version="${MRTRUST_VERSION}"
           package_root="dist/MrTrust-${version}"
           rm -rf "$package_root" "dist/MrTrust-${version}.zip"
           mkdir -p "$package_root"
@@ -54,8 +55,8 @@ jobs:
       - name: Upload release artifact
         uses: actions/upload-artifact@v3
         with:
-          name: MrTrust-0.1.3
+          name: MrTrust-${{ env.MRTRUST_VERSION }}
-          path: dist/MrTrust-0.1.3.zip
+          path: dist/MrTrust-${{ env.MRTRUST_VERSION }}.zip
 
       - name: Attach ZIP to Gitea release
         if: github.ref == 'refs/heads/main'
@@ -64,7 +65,8 @@ jobs:
           GITEA_TOKEN: ${{ secrets.GITHUB_TOKEN }}
         run: |
           set -euo pipefail
-          version="0.1.3"
+          version="${MRTRUST_VERSION}"
+          asset_name="MrTrust-${version}.zip"
           api="https://git.wilkensxl.de/api/v1/repos/MrSphay/MrTrust"
           release_response="$(mktemp)"
           status="$(curl -sS -o "$release_response" -w "%{http_code}" -H "Authorization: token ${GITEA_TOKEN}" "${api}/releases/tags/v${version}")"
@@ -98,8 +100,27 @@ PY
             echo "Could not resolve release id for v${version}" >&2
             exit 1
           fi
+          existing_asset_id="$(RELEASE_JSON="$release_json" ASSET_NAME="$asset_name" python3 <<'PY'
+import json
+import os
+import sys
+
+asset_name = os.environ["ASSET_NAME"]
+release = json.loads(os.environ["RELEASE_JSON"])
+for asset in release.get("assets", []):
+    if asset.get("name") == asset_name:
+        print(asset.get("id", ""))
+        break
+PY
+)"
+          if [ -n "$existing_asset_id" ]; then
+            curl -fsS \
+              -X DELETE \
+              -H "Authorization: token ${GITEA_TOKEN}" \
+              "${api}/releases/${release_id}/assets/${existing_asset_id}"
+          fi
           curl -fsS \
             -X POST \
             -H "Authorization: token ${GITEA_TOKEN}" \
-            -F "attachment=@dist/MrTrust-${version}.zip" \
+            -F "attachment=@dist/${asset_name}" \
-            "${api}/releases/${release_id}/assets?name=MrTrust-${version}.zip"
+            "${api}/releases/${release_id}/assets?name=${asset_name}"