Update CONTRIBUTING.md

[macneale4]

The unicode char at the end of the request for stars wasn't rendering. replaced with a ⭐

[github-actions]

	Main	PR
covering_index_scan_postgres	368.33/s	367.00/s	-0.4%
index_join_postgres	154.76/s	153.92/s	-0.6%
index_join_scan_postgres	185.35/s	184.07/s	-0.7%
index_scan_postgres	12.63/s	12.77/s	+1.1%
oltp_point_select	2813.23/s	2854.93/s	+1.4%
oltp_read_only	1891.15/s	1897.03/s	+0.3%
select_random_points	112.64/s	114.79/s	+1.9%
select_random_ranges	132.15/s	132.50/s	+0.2%
table_scan_postgres	12.12/s	12.10/s	-0.2%
types_table_scan_postgres	5.76/s	5.74/s	-0.4%

[github-actions]

	Main	PR
Total	42090	42090
Successful	15344	15344
Failures	26746	26746
Partial Successes1	5232	5232

	Main	PR
Successful	36.4552%	36.4552%
Failures	63.5448%	63.5448%

Footnotes

1. These are tests that we're marking as Successful, however they do not match the expected output in some way. This is due to small differences, such as different wording on the error messages, or the column names being incorrect while the data itself is correct. ↩

[zachmu]

LGTM