Revert "Add git coommit completions" (#868)

Reverts #854

This PR broke the git aliases
https://github.com/nushell/nu_scripts/blob/main/aliases/git/git-aliases.nu
so I'm reverting it.

custom-completions/git/git-completions.nu

@@ -428,46 +428,8 @@ export extern "git diff" [
 export extern "git commit" [
  --all(-a) # automatically stage all modified and deleted files
  --amend # amend the previous commit rather than adding a new one
- --message(-m): string # specify the commit message rather than opening an editor
+ --message(-m)  # specify the commit message rather than opening an editor
  --no-edit # don't edit the commit message (useful with --amend)
- --reuse-message(-C): string # reuse the message from a previous commit
- --reedit-message(-c): string # reuse and edit message from a commit
- --fixup: string # create a fixup/amend commit
- --squash: string # squash commit for autosquash rebase
- --reset-author # reset author information
- --short # short-format output for dry-run
- --branch # show branch info in short-format
- --porcelain # porcelain-ready format for dry-run
- --long # long-format output for dry-run
- --null(-z) # use NUL instead of LF in output
- --file(-F): string # read commit message from file
- --author: string # override commit author
- --date: string # override author date
- --template(-t): string # use commit message template file
- --signoff(-s) # add Signed-off-by trailer
- --no-signoff # do not add Signed-off-by trailer
- --trailer: string # add trailer to commit message
- --no-verify(-n) # bypass pre-commit and commit-msg hooks
- --verify # do not bypass pre-commit and commit-msg hooks
- --allow-empty # allow commit with no changes
- --allow-empty-message # allow commit with empty message
- --cleanup: string # cleanup commit message
- --edit(-e) # edit commit message
- --no-edit # do not edit commit message
- --amend # amend previous commit
- --include(-i) # include given paths in commit
- --only(-o) # commit only specified paths
- --pathspec-from-file: string # read pathspec from file
- --pathspec-file-nul # use NUL character for pathspec file
- --untracked-files(-u): string # show untracked files
- --verbose(-v) # show diff in commit message template
- --quiet(-q) # suppress commit summary
- --dry-run # show paths to be committed without committing
- --status # include git-status output in commit message
- --no-status # do not include git-status output
- --gpg-sign(-S):string # GPG-sign commit
- --no-gpg-sign # do not GPG-sign commit
- ...pathspec: string # commit files matching pathspec
 ]
 
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