Run spec_guards only when spec files changed [ci skip]

.github/workflows/spec_guards.yml

@@ -2,21 +2,13 @@ name: Rubyspec Version Guards Check
 
 on:
   push:
-    paths-ignore:
-      - 'doc/**'
-      - '**.md'
-      - '**.rdoc'
-      - '**/.document'
-      - '**.[1-8]'
-      - '**.ronn'
+    paths:
+      - 'spec/**'
+      - '!spec/*.md'
   pull_request:
     paths-ignore:
-      - 'doc/**'
-      - '**.md'
-      - '**.rdoc'
-      - '**/.document'
-      - '**.[1-8]'
-      - '**.ronn'
+      - 'spec/**'
+      - '!spec/*.md'
 
 concurrency:
   group: ${{ github.workflow }} / ${{ startsWith(github.event_name, 'pull') && github.ref_name || github.sha }}