ci: restrict test generator to .go files

The integration test generator scanned all files under integration/
with ripgrep, matching func Test* patterns in README.md code examples
(TestMyScenario, TestRouteAdvertisementBasic). Add --type go to limit
the search to Go source files.

.github/workflows/gh-action-integration-generator.go

@@ -66,6 +66,7 @@ func findTests() []string {
 	}
 
 	args := []string{
+		"--type", "go",
 		"--regexp", "func (Test.+)\\(.*",
 		"../../integration/",
 		"--replace", "$1",