fix: respect current EOL in gitignore

[cristiand391]

Fixes: #301

Problem:
sf-install reads the .gitignore in the project and tries to split the content by \n (even on windows).
This messes up your gitignore if it uses CRLF (most common on windows but can happen on linux/mac too) like in the linked issue above.

dev-scripts now will detect the EOL used by the local file and use that for parsing the content and final write.
We can't use node's os.EOL because it assumes unix === LF and win === CRLF.

same change in sf-clean

NOTE:
there's a file check done here to see if the .gitignore in the project matches the template:

dev-scripts/utils/standardize-files.js

Line 79 in e2efc93

const copied = copyFile(gitignoreSourcePath, gitignoreTargetPath);

https://github.com/forcedotcom/dev-scripts/blob/e2efc93a4af12dc5953d1beb673cc768a7e620a6/utils/standardize-files.js#L35C1-L48C2

isDifferent just normalizes line endings for comparision so that's left as is.

Testing

1. clone plugin-info (or any other of our plugins)
2. make .gitignore use CRLF (open in vscode click on LF at the bottom of the screen, choose CRLF and save the file
   

sf-install

now run yarn (will run sf-install), it'll print standardizing config files for plugin-info and if you open the file you'll see it's missing the CLEAN ALL items and other stuff.

sf-clean

restore changes (clean git status), redo step 1 & 2 and run yarn clean, will print:

➜  plugin-info git:(main) ✗ yarn clean
yarn run v1.22.19
$ sf-clean
,oclif.lockfest.json

but the gitignore have more stuff in it that's missing because of CRLF.

install the prerelease in this branch and the steps above should work wether gitignore uses LF or CRLF on any os.

@W-15748612@

[mdonnalley]

QA

🟢 line endings are preserved on sf-install when using LF
🟢 line endings are preserved on sf-install when using CRLF
🟢 line endings are preserved on sf-clean when using LF
🟢 line endings are preserved on sf-clean when using CRLF