[Github] Reformat strings for code format action (#75764)

Before this patch, there was a regression in comment formatting due to
some code formatting in bd3e8eb6. This
was fixed in 428660cf. Github interprets
a tab before a string as starting code formatting. The message that
indicted the code formatting in a PR had been fixed was refactored to a
python multi-line string, but with a tab in front, causing these
messages to be rendered as code blocks in Github, instead of as
intended. This patch builds upon the original fix to reformat the
strings so that they fit within ~80 character lines and are simpler to
modify in the future, hopefully removing traps like the one that caused
the original issue.