Specify python3 instead of python3.7 for pre-commit

[pmossman]

On an M1 mac with python3.7 and python3.10 installed, I see the following error any time I attempt to commit:

[INFO] Installing environment for https://github.com/johann-petrak/licenseheaders.git.
[INFO] Once installed this environment will be reused.
[INFO] This may take a few minutes...
An unexpected error has occurred: CalledProcessError: command: ('/Users/parker/.pyenv/versions/3.10.0/bin/python3.10', '-mvirtualenv', '/Users/parker/.cache/pre-commit/repoyd65z1bj/py_env-python3.7', '-p', 'python3.7')
return code: 1
expected return code: 0
stdout:
    RuntimeError: failed to find interpreter for Builtin discover of python_spec='python3.7'

stderr: (none)
Check the log at /Users/parker/.cache/pre-commit/pre-commit.log

Changing the default language version from python3.7 to python3 fixes this issue for me.

@sergei-solonitcyn, I'm not sure what the wider implications of such a change would be but if it seems safe to you, it'd help out M1 users who are running into this issue. (@edgao confirmed he has the same issue on his M1)

[sergei-solonitcyn]

I believe, installing python3.7 and using it in your development environment should fix it. And that would help to avoid making unsupported changes.

But from my perspective this change is not expected to break anything, so I don't mind.

[pmossman]

I have python3.7 installed and tried using it in my development environment, but the issue remained. Here's what it looks like:

❯ git commit -m "try reverting back to 3.7"
[WARNING] Unstaged files detected.
[INFO] Stashing unstaged files to /Users/parker/.cache/pre-commit/patch1641509857-30749.
[INFO] Installing environment for https://github.com/johann-petrak/licenseheaders.git.
[INFO] Once installed this environment will be reused.
[INFO] This may take a few minutes...
[INFO] Restored changes from /Users/parker/.cache/pre-commit/patch1641509857-30749.
An unexpected error has occurred: CalledProcessError: command: ('/Users/parker/.pyenv/versions/3.10.0/bin/python3.10', '-mvirtualenv', '/Users/parker/.cache/pre-commit/repoyd65z1bj/py_env-python3.7', '-p', 'python3.7')
return code: 1
expected return code: 0
stdout:
    RuntimeError: failed to find interpreter for Builtin discover of python_spec='python3.7'

stderr: (none)
Check the log at /Users/parker/.cache/pre-commit/pre-commit.log


❯ pyenv version
3.7.9 (set by /Users/parker/code/airbyte/.python-version)

So I think if you don't mind, Sergei, I'll merge this in to avoid spending more time digging/debugging. If I run into other python version-related issues with this M1, I may revisit this in the future to see if I can determine a root cause.