Replace gitea-release plugin with curl-based release upload

Uses basic auth (droneci user) and Gitea API directly to create
the release and upload the binary asset.
Fix the golangci-lint issues

.woodpecker/release.yaml

@@ -15,23 +15,16 @@ steps:
     depends_on: [test]
 
   - name: release
-    image: git.unkin.net/unkin/almalinux9-base:20260325
+    image: alpine/curl
     environment:
       DRONECI_PASSWORD:
         from_secret: DRONECI_PASSWORD
     commands:
       - |
-        PREV_TAG=$(git describe --tags --abbrev=0 HEAD^ 2>/dev/null || echo "")
-        if [ -n "$PREV_TAG" ]; then
-          NOTES=$(git log "${PREV_TAG}..${CI_COMMIT_TAG}" --merges --pretty=format:"- %s")
-        else
-          NOTES=$(git log --merges --pretty=format:"- %s")
-        fi
-        BODY=$(printf '%s' "$NOTES" | sed 's/"/\\"/g; s/$/\\n/' | tr -d '\n')
         RELEASE_ID=$(curl -sf -X POST "https://git.unkin.net/api/v1/repos/${CI_REPO}/releases" \
           -u "droneci:$DRONECI_PASSWORD" \
           -H "Content-Type: application/json" \
-          -d "{\"tag_name\":\"${CI_COMMIT_TAG}\",\"name\":\"${CI_COMMIT_TAG}\",\"body\":\"${BODY}\"}" \
+          -d "{\"tag_name\":\"${CI_COMMIT_TAG}\",\"name\":\"${CI_COMMIT_TAG}\"}" \
           | grep -o '"id":[0-9]*' | head -1 | cut -d: -f2)
         curl -sf -X POST "https://git.unkin.net/api/v1/repos/${CI_REPO}/releases/${RELEASE_ID}/assets" \
           -u "droneci:$DRONECI_PASSWORD" \