Fix filename for .spectral.yaml (#26828)

Mixed up yml vs. yaml previously.

Author: silverwind

.github/workflows/files-changed.yml

@@ -81,4 +81,4 @@ jobs:
               - "Makefile"
               - "package.json"
               - "package-lock.json"
-              - ".spectral.yml"
+              - ".spectral.yaml"