Allow "/" in metrics validator

[awdavidson]

Changes Proposed in this PR

• Allow '/' in metrics validator, this resolves issues such as

airflow.exceptions.InvalidStatsNameException: The stat name (dag_processing.processes,file_path=/mnt/c/Users/user/Documents/GitHub/airflow-dir/test_dag.py,action=finish) has to be composed of ASCII alphabets, numbers, or the underscore, dot, or dash characters.
[2023-04-18T12:21:39.738-0400] {stats.py:245} ERROR - Invalid stat name: dag_processing.processes,file_path=/mnt/c/Users/user/Documents/GitHub/airflow-dir/test_dag.py,action=start.
Traceback (most recent call last):
File "/mnt/c/Users/user/Documents/GitHub/airflow-dir/venv/lib/python3.9/site-packages/airflow/stats.py", line 242, in wrapper
stat = handler_stat_name_func(stat)
File "/mnt/c/Users/user/Documents/GitHub/airflow-dir/venv/lib/python3.9/site-packages/airflow/stats.py", line 210, in stat_name_default_handler
raise InvalidStatsNameException(
airflow.exceptions.InvalidStatsNameException: The stat name (dag_processing.processes,file_path=/mnt/c/Users/user/Documents/GitHub/airflow-dir/test_dag.py,action=start) has to be composed of ASCII alphabets, numbers, or the underscore, dot, or dash characters.
[2023-04-18T12:21:51.375-0400] {stats.py:245} ERROR - Invalid stat name: dag_processing.processes,file_path=/mnt/c/Users/user/Documents/GitHub/airflow-dir/test_dag.py,action=finish.

closes: #30716

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[potiuk]

Two asks:

1. Can you please add a unit test for that
2. This look like a bug-fix - can you please cherry-pick (with -x) this change after I merge it to v2-10-test targeted-PR ?

[potiuk]

Some static checks to fix. I recommend installing pre-commit - it will solve problems for you

[potiuk]

Nice!

[shalberd]

Very nice indeed, thank you so very much. @potiuk will this be backported and included in 2.10.3 or only in a future Airflow v3?

[potiuk]

Ah ... It should be .. but I forgot to put the label on it... So let me try to cherry-pick it now.

[potiuk]

#44515