gh-100072: only trigger netlify builds for doc changes (#100074)

Co-authored-by: Hugo van Kemenade <[email protected]>

Author: sobolevn

netlify.toml

@@ -2,7 +2,10 @@
     base = "Doc/"
     command = "make html"
     publish = "build/html"
+    # Do not trigger netlify builds if docs were not changed.
+    # Changed files should be in sync with `.github/workflows/doc.yml`
+    ignore = "git diff --quiet $CACHED_COMMIT_REF $COMMIT_REF . ../netlify.toml"
 
 [build.environment]
   PYTHON_VERSION = "3.8"
-  IS_DEPLOYMENT_PREVIEW = "true"
+  IS_DEPLOYMENT_PREVIEW = "true"