src: use for loop in Dotenv::GetPathFromArgs

[avivkeller]

This PR replaces the old while loop with a newer for loop.

Fixes the following edge cases:

node script.js --env-file .env
node --env-file-ABCD .env
node -- --env-file .env
node -invalid --env-file .env # this will error, but the env file is still processed

Unfortunately, this introduces an edge case where some argument parameters, such as --eval <...> cause any future --env-file arguments to be ignored.

node --eval "1+1" --env-file notparsed.env

Fixes#54255
Fixes#54232
Related to #54237

[anonrig]

Can you add a cc test for testing only this function and every edge case you're targeting?

[avivkeller]

@anonrig would you mind restarting the Github CI now that #54391 landed?

Actually I'm going to rebase for it.

[codecov]

Codecov Report

Attention: Patch coverage is 80.00000% with 2 lines in your changes missing coverage. Please review.

Project coverage is 87.07%. Comparing base (2c14615) to head (35c4dae).
Report is 268 commits behind head on main.

Files with missing lines	Patch %	Lines
src/node_dotenv.cc	80.00%	0 Missing and 2 partials ⚠️

Additional details and impacted files

@@ Coverage Diff @@## main #54385 +/- ##
==========================================
- Coverage 87.08% 87.07% -0.01% 
==========================================
Files 648 648 Lines 182341 182338 -3 Branches 34982 34981 -1 ==========================================
- Hits 158783 158773 -10 - Misses 16831 16833 +2 - Partials 6727 6732 +5 

Files with missing lines	Coverage Δ
src/node_dotenv.cc	81.36% <80.00%> (-0.35%)	⬇️

... and 24 files with indirect coverage changes

[avivkeller]

@anonrig Do you think this should land (eventually), or it should be held-off, and a redone GetPathFromArgs would be better, one that doesn't have these edge cases?

[avivkeller]

Closing in favor of #54913