[Possible Bug] --cruft option not work with git gc --prune=now

I am trying to use the --cruft feature of git gc, and everything works well, but when I combine it with --prune=now, I notice that no cruft package is generated, which is very strange. So I turned on trace and checked: instead of executing `git repack --cruft`, it executed `git repack -d -l -a`. Is this normal? If `git gc --cruft --prune=now` doesn't work as expected, it won't be safe to further execute `git gc --cruft --expire-to=<dir> --prune=now`(in my another patch).

I checked the code, and it appears that add_repack_all_option() first processes `--prune=now` before handling `--cruft` option.

If this is a bug, I am willing to propose a patch to fix it.

```shell GIT_TRACE=1 git gc --prune=now --cruft 19:56:54.132263 git.c:479 trace: built-in: git gc --prune=now --cruft 19:56:54.137004 run-command.c:666 trace: run_command: git pack-refs --all --prune 19:56:54.137087 run-command.c:758 trace: start_command: /Users/adl/libexec/git-core/git pack-refs --all --prune 19:56:54.152233 git.c:479 trace: built-in: git pack-refs --all --prune 19:56:54.166598 run-command.c:666 trace: run_command: git reflog expire --all 19:56:54.166705 run-command.c:758 trace: start_command: /Users/adl/libexec/git-core/git reflog expire --all 19:56:54.181965 git.c:479 trace: built-in: git reflog expire --all 19:56:54.184495 run-command.c:666 trace: run_command: git repack -d -l -a 19:56:54.184571 run-command.c:758 trace: start_command: /Users/adl/libexec/git-core/git repack -d -l -a 19:56:54.196211 git.c:479 trace: built-in: git repack -d -l -a 19:56:54.198260 run-command.c:666 trace: run_command: git pack-objects --local --delta-base-offset objects/pack/.tmp-59391-pack --keep-true-parents --honor-pack-keep --non-empty --all --reflog --indexed-objects --write-bitmap-index-quiet 19:56:54.198304 run-command.c:758 trace: start_command: /Users/adl/libexec/git-core/git pack-objects --local --delta-base-offset objects/pack/.tmp-59391-pack --keep-true-parents --honor-pack-keep --non-empty --all --reflog --indexed-objects --write-bitmap-index-quiet 19:56:54.209384 git.c:479 trace: built-in: git pack-objects --local --delta-base-offset objects/pack/.tmp-59391-pack --keep-true-parents --honor-pack-keep --non-empty --all --reflog --indexed-objects --write-bitmap-index-quiet Enumerating objects: 512819, done. Counting objects: 100% (512819/512819), done. Delta compression using up to 12 threads Compressing objects: 100% (237575/237575), done. Writing objects: 100% (512819/512819), done. Selecting bitmap commits: 23999, done. Building bitmaps: 100% (309/309), done. Total 512819 (delta 116078), reused 512819 (delta 116078), pack-reused 0 (from 0) 19:57:12.783287 run-command.c:666 trace: run_command: git prune --expire now 19:57:12.783887 run-command.c:758 trace: start_command: /Users/adl/libexec/git-core/git prune --expire now 19:57:12.799337 git.c:479 trace: built-in: git prune --expire now 19:57:12.802050 run-command.c:666 trace: run_command: git worktree prune --expire 3.months.ago 19:57:12.802115 run-command.c:758 trace: start_command: /Users/adl/libexec/git-core/git worktree prune --expire 3.months.ago 19:57:12.812977 git.c:479 trace: built-in: git worktree prune --expire 3.months.ago 19:57:12.814412 run-command.c:666 trace: run_command: git rerere gc 19:57:12.814476 run-command.c:758 trace: start_command: /Users/adl/libexec/git-core/git rerere gc 19:57:12.825732 git.c:479 trace: built-in: git rerere gc ```

-- ZheNing Hu