Polish lint and styling actions

[philipp-baumann]

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[philipp-baumann]

• avoid race conditions: like implemented in this PR: ccao-data/model-res-avm#244

[philipp-baumann]

take home/lessions learnt:

• styler action: tweak styling in this action so that the R setup is bootstrapped via nix and our root default.nix with the necessary dev packages. adapt https://github.com/r-lib/httr2/blob/main/.github/workflows/pr-commands.yaml ; we now have auto-fixing in the PR, only if we have changes.

• combine styling and linting. for linting, {lintr} is used. the styler action can write and auto-commit fixes, however the linter is not an auto-formatter. styler does very basic styling, and has caveats, and unfortunately has no auto-fixing of the line length implemented.

• I disabled the pre-commit setup provided via {precommit}. it seems unrealistic and not straight-forward to port a pre-commit hook specifically for R into a nix-approach. Mainly because all R-agnostic tooling in pre-commit is initialized via python virtualenv and also mainly using {renv}, which very cumbersome and also not appropriate for porting into a clean nix approach. There is various race conditions and also there is currently problems with the cache (via R.cache), which are currently not fixed in styler.