[8.18] (backport #8498) Exclude NOTICE files from merge conflict detection. (#8531)

* Exclude NOTICE files from merge conflict detection. (#8498)

(cherry picked from commit d3bc5d9)

# Conflicts:
#	.pre-commit-config.yaml

* Fix conflict in .pre-commit-config.yaml

---------

Co-authored-by: Craig MacKenzie <[email protected]>

Author: mergify[bot]

.pre-commit-config.yaml

@@ -7,3 +7,5 @@ repos:
     -   id: check-shebang-scripts-are-executable
         exclude: (.*/.*.(tmpl|tftpl)$)
     -   id: check-merge-conflict
+        args: ['--assume-in-merge']
+        exclude: (^NOTICE.*\.txt$)