ci: bump go test per-package timeout from 5m to 10m

The model/vfs package now exercises three backends (afero, swift, s3)
plus a second MinIO container for S3UploadErrorPropagation, pushing the
package past the previous 5-minute per-package limit on GH runners.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Author: Crash--

.github/workflows/go-tests.yml

@@ -64,4 +64,4 @@ jobs:
           cache: true
 
       - name: Run tests
-        run: go test -p 1 -timeout 5m ./...
+        run: go test -p 1 -timeout 10m ./...