Labeler: Add labeler glob patterns for CI

We have a "Category: CI" label in GH issues and PRs, but there is no
labeler rule to automatically mark PRs as such.

This adds a labeler rule to automatically add the "Category: CI" label
if the PR changes _any_ file in:

  - '.circleci/*'
  - '.github/*'

If all the changes are within these files, it will _not_ be labelled.

 - '.github/ISSUE_TEMPLATE/*'
 - '.github/lsan-suppressions.txt'

Author: Ayesh

.github/labeler.yml

@@ -20,6 +20,14 @@
         - scripts/**/*
         - win32/build/**/*
 
+"Category: CI":
+  - changed-files:
+      - any-glob-to-any-file:
+          - .circleci/**
+          - .github/**
+          - '!.github/lsan-suppressions.txt'
+          - '!.github/ISSUE_TEMPLATE/**'
+
 "Extension: bcmath":
   - changed-files:
       - any-glob-to-any-file: