fix ci: replace drone-git-push plugin with git commands

appleboy/drone-git-push treats 'path' as a chdir directory, not a file
to commit. Use alpine/git with explicit git add/commit/push instead.

.woodpecker/ci.yml

@@ -46,19 +46,20 @@ steps:
       - test
 
   - name: commit-badge
-    image: appleboy/drone-git-push
+    image: alpine/git
     failure: ignore
-    settings:
+    environment:
-      remote: http://gitea:3000/homelab/stack.git
+      REGISTRY_USER:
-      branch: main
-      author_name: woodpecker-ci
-      author_email: ci@fhirworx.io
-      commit_message: "update coverage badge [skip ci]"
-      path: coverage.svg
-      username:
         from_secret: registry_user
-      password:
+      REGISTRY_PASS:
         from_secret: registry_pass
+    commands:
+      - git config user.name woodpecker-ci
+      - git config user.email ci@fhirworx.io
+      - git add coverage.svg
+      - git diff --cached --quiet && echo "no change" && exit 0
+      - git commit -m "update coverage badge [skip ci]"
+      - git push http://$REGISTRY_USER:$REGISTRY_PASS@gitea:3000/homelab/stack.git HEAD:main
     when:
       - branch: main
         event: push