ci: pin playwright to 1.61.1 matching runner image

Floating "^1" resolved to 1.61.1 while the e2e container was pinned
to v1.59.0-jammy, so its browser builds were missing at launch. Pin the
dep exact and bump the image so the two versions move together.

.gitea/workflows/ci.yml

@@ -39,7 +39,7 @@ jobs:
     needs: verify
     runs-on: ubuntu-latest
     container:
-      image: mcr.microsoft.com/playwright:v1.59.0-jammy
+      image: mcr.microsoft.com/playwright:v1.61.1-jammy
     steps:
       - uses: actions/checkout@v4
       - name: Enable Corepack