limit mergify auto doc label (#2519)

Summary:

make mergify only auto label if there are ONLY
examples/docs changes rather than whenever there are examples/docs
changes

---------

Signed-off-by: HDCharles <charlesdavidhernandez@gmail.com>
Signed-off-by: HDCharles <39544797+HDCharles@users.noreply.github.com>
Co-authored-by: Dipika Sikka <dipikasikka1@gmail.com>

Author: HDCharles

.github/mergify.yml

@@ -47,6 +47,11 @@ pull_request_rules:
           - files~=^[^/]+\.md$
           - files~=^docs/
           - files~=^examples/
+      - -files~=^src/
+      - -files~=^tests/
+      - -files~=^\.github/
+      - -files~=^Makefile$
+      - -files~=^pyproject\.toml$
     actions:
       label:
         add: