### Summary

See: https://github.com/ansible/ansible/blob/devel/lib/ansible/modules/git.py#L760 :

```py
            repo_path = os.path.join(repo_path.split('.git')[0], gitdir)
```

the intention of this code seems to be to strip `.git` from the end of the path.

If the repo path contains `.git` anywhere, like `/tmp/music.gittern/myrepo`, tasks will unexpectedly fail:

```
fatal: [localhost]: FAILED! => {"changed": false, "details": "/tmp/music/../.git/modules/submodule is not a directory", "msg": "Current repo does not have a valid reference to a separate Git dir or it refers to the invalid path"}
```

For a playbook like:
```yaml
---
- hosts: localhost
  tasks:
   - name: test git
     git: 
        repo: ...
        dest: /tmp/music.gittern/myrepo/submodule
```

I can't tell if this is a potential security issue or just an unexpected corner case. What I am pretty sure I can tell, is that that's not how one strips `.git` from the end of a path.

### Issue Type

Bug Report

### Component Name

git

### Ansible Version

```console
$ ansible --version
2.11
```


### Configuration

```console
$ ansible-config dump --only-changed
ANSIBLE_NOCOWS(/home/enrico/dev/transilience/ansible.cfg) = True
```


### OS / Environment

Debian Bullseye

### Steps to Reproduce

Use submodules in a repo whose path contains `.git` anywhere as part of a file name.
For example:
```yaml
---
- hosts: localhost
  tasks:
   - name: test git
     git: 
        repo: ...
        dest: /tmp/music.gittern/myrepo/submodule
```

### Expected Results

I'd expect directory names like `gato.gito` not to be interpreted specially by mistake

### Actual Results

```console
fatal: [localhost]: FAILED! => {"changed": false, "details": "/tmp/music/../.git/modules/submodule is not a directory", "msg": "Current repo does not have a valid reference to a separate Git dir or it refers to the invalid path"}
```


### Code of Conduct

- [X] I agree to follow the Ansible Code of Conduct
relocate_repo(module, result, separate_git_dir, repo_path, dest)
                    repo_path = separate_git_dir
        except (IOError, ValueError) as err:
            
            """``.git`` file does not have a valid format for detached Git dir."""
            module.fail_json(
                msg='Current repo does not have a valid reference to a '
                'separate Git dir or it refers to the invalid path',
                details=to_text(err),
            )
        gitconfig = os.path.join(repo_path, 'config')
    
    
    
    ssh_wrapper = write_ssh_wrapper(module.tmpdir)
    set_git_ssh(ssh_wrapper, key_file, ssh_opts)
    module.add_cleanup_file(path=ssh_wrapper)
    git_version_used = git_version(git_path, module)
    if depth is not None and git_version_used < LooseVersion('1.9.1'):
        module.warn("git version is too old to fully support the depth argument. Falling back to full checkouts.")
        depth = None
    recursive = module.params['recursive']
    track_submodules = module.params['track_submodules']
    result.update(before=None)
    local_mods = False
    if (dest and not os.path.exists(gitconfig)) or (not dest and not allow_clone):