chore: Add .git-blame-ignore-revs (#2059)

This lets us ignore large changes in blame. Use it
to ignore the Protobuf file formatter commit.

See https://docs.github.com/en/repositories/working-with-files/using-files/viewing-a-file#ignore-commits-in-the-blame-view
for more information.

.git-blame-ignore-revs

@@ -0,0 +1,2 @@
+# Formatted all Protobuf files
+f69fbf22552deac9ec81503d629fb70919acabdb