.github: fix quoting in docs check error message (#568)

See
https://github.com/modelcontextprotocol/go-sdk/actions/runs/18410542710/job/52464273952?pr=567

Apparently, back-ticked code snippets are not rendered, leading to
non-sensical suggestions from the docs check failure.

Remove back-ticks for now.

.github/workflows/docs-check.yml

@@ -25,9 +25,9 @@ jobs:
           if [ -n "$(git status --porcelain)" ]; then
             echo "ERROR: docs are not up-to-date!"
             echo ""
-            echo "The docs differ from what would be generated by `go generate ./...`."
+            echo "The docs differ from what would be generated by go generate ./..."
             echo "Please update internal/**/*.src.md instead of directly editing README.md or docs/ files,"
-            echo "then run `go generate ./...` to regenerate docs."
+            echo "then run go generate ./... to regenerate docs."
             echo ""
             echo "Changes:"
             git status --porcelain