minor #43697 [Dotenv] Fix testLoadEnv() .env.dist isolation (fancyweb)
minor #43697 [Dotenv] Fix testLoadEnv() .env.dist isolation (fancyweb)

This PR was merged into the 4.4 branch.

Discussion
----------

[Dotenv] Fix testLoadEnv() .env.dist isolation

| Q             | A
| ------------- | ---
| Branch?       | 4.4
| Bug fix?      | no
| New feature?  | no
| Deprecations? | no
| Tickets       | -
| License       | MIT
| Doc PR        | -

Sorry but I did not catch everything in the first one.

When `.env.dist` is tested, `.env.local` , `.env.dev` and `.env.dev.local` still exists and "override" defined vars in `.env.dist`. I guess that's why you used another var (`BAR`). It makes more sense to me to actually test it "in isolation" since we don't test anything about the override right now.

Also, I applied some minor changes to minimize the diff on changes I'm working on for adding `$overrideExistingVars` to `loadEnv()` and `bootEnv()`.

Commits
-------

ae63960264 [Dotenv] Fix testLoadEnv() .env.dist isolation

mpdude/symfony,curry684/symfony,HeahDude/symfony,ogizanagi/symfony,mpdude/symfony,hhamon/symfony,symfony/symfony,curry684/symfony,hhamon/symfony,paradajozsef/symfony,ogizanagi/symfony,curry684/symfony,tucksaun/symfony,xabbuh/symfony,symfony/symfony,ro0NL/symfony,phramz/symfony,ogizanagi/symfony,d-ph/symfony,HeahDude/symfony,ro0NL/symfony,zerkms/symfony,zerkms/symfony,d-ph/symfony,paradajozsef/symfony,hhamon/symfony,d-ph/symfony,paradajozsef/symfony,stof/symfony,tucksaun/symfony,derrabus/symfony,Tobion/symfony,nicolas-grekas/symfony,nicolas-grekas/symfony,xabbuh/symfony,sgehrig/symfony,xabbuh/symfony,damienalexandre/symfony,Tobion/symfony,tucksaun/symfony,derrabus/symfony,HeahDude/symfony,damienalexandre/symfony,zerkms/symfony,phramz/symfony,Tobion/symfony,ro0NL/symfony,sgehrig/symfony,nicolas-grekas/symfony,stof/symfony,derrabus/symfony,d-ph/symfony,nicolas-grekas/symfony,damienalexandre/symfony,stof/symfony,mpdude/symfony,xabbuh/symfony,damienalexandre/symfony,ogizanagi/symfony,zerkms/symfony,tucksaun/symfony,phramz/symfony,mpdude/symfony,symfony/symfony,curry684/symfony,hhamon/symfony,symfony/symfony,sgehrig/symfony,sgehrig/symfony,derrabus/symfony,ro0NL/symfony,phramz/symfony,stof/symfony,Tobion/symfony,paradajozsef/symfony,HeahDude/symfony