Support absolute disabled_globs (#25755)

Closes: #25556

We were always comparing `disabled_globs` against the relative file
path, we'll now use the absolute path if the glob is also absolute.

Release Notes:

- Support absolute globs in `edit_predictions.disabled_globs`

assets/settings/default.json

@@ -829,6 +829,8 @@
     // A list of globs representing files that edit predictions should be disabled for.
     // There's a sensible default list of globs already included.
     // Any addition to this list will be merged with the default list.
+    // Globs are matched relative to the worktree root,
+    // except when starting with a slash (/) or equivalent in Windows.
     "disabled_globs": [
       "**/.env*",
       "**/*.pem",