Ignore pyupgrade commit for git blame (PyGithub#1785)

s-t-e-v-e-n-k · web-flow · commit f299699ccd75 · 2020-12-15T14:13:05.000+11:00
Since the pyupgrade commit makes a large amount of changes, ignore the
commit by default with git blame.
diff --git a/.git-blame-ignore-revs b/.git-blame-ignore-revs
@@ -6,3 +6,6 @@
 
 # Format with new black
 07e29fe014b7e214e72b51129fbef55468a7309d
+
+# Add pyupgrade to pre-commit
+e113e37de1ec687c68337d777f3629251b35ab28
