Correct MySQL backend version in Breeze docs (apache#35161)

root@d20033cda4df:/opt/airflow# breeze --python 3.8 --backend mysql --mysql-version 8

Provided outdated value 8 for parameter mysql_version. Will use 8.0 instead
Good version of Docker: 24.0.6.
Good version of docker-compose: 2.23.0

BREEZE.rst

@@ -423,7 +423,7 @@ as follows:
 
 .. code-block:: bash
 
-    breeze --python 3.8 --backend mysql --mysql-version 8
+    breeze --python 3.8 --backend mysql --mysql-version 8.0
 
 .. note:: Note for Windows WSL2 users
 
@@ -439,7 +439,7 @@ Try adding ``--builder=default`` to your command. For example:
 
 .. code-block:: bash
 
-    breeze --builder=default --python 3.8 --backend mysql --mysql-version 8
+    breeze --builder=default --python 3.8 --backend mysql --mysql-version 8.0
 
 The choices you make are persisted in the ``./.build/`` cache directory so that next time when you use the
 ``breeze`` script, it could use the values that were used previously. This way you do not have to specify