Cleanup: remove stale version variable and fix typos in comments

[romanc]

Description

This PR removes an old/stale hard-coded version number from pyFV3/__init__.py and fixes a bunch of typos in comments.

How Has This Been Tested?

Ran pre-commit locally 😉

Checklist:

• My code follows the style guidelines of this project
• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas: N/A
• I have made corresponding changes to the documentation: N/A
• My changes generate no new warnings
• Any dependent changes have been merged and published in downstream modules: N/A
• New check tests, if applicable, are included: N/A
• Targeted model if this changed was triggered by a model need/shortcoming: N/A

[romanc]

@FlorianDeconinck random stuff I found while digging in the pyFV3 stencils during the dace bridge debug sessions. Happy Friday afternoon!

[FlorianDeconinck]

LGTM