### 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
branches = get_branches(git_path, module, dest)
    for branch in branches:
        if branch.startswith('* ') and ('no branch' in branch or 'detached from' in branch or 'detached at' in branch):
            return True
    return False
def get_repo_path(dest, bare):
    if bare:
        repo_path = dest
    else:
        repo_path = os.path.join(dest, '.git')
    
    
    if os.path.isfile(repo_path):
        with open(repo_path, 'r') as gitfile:
            data = gitfile.read()
        ref_prefix, gitdir = data.rstrip().split('gitdir: ', 1)
        if ref_prefix:
            raise ValueError('.git file has invalid git dir reference format')
        
        if os.path.isabs(gitdir):
            repo_path = gitdir
        else:
            repo_path = os.path.join(repo_path.split('.git')[0], gitdir)
        if not os.path.isdir(repo_path):
            raise ValueError('%s is not a directory' % repo_path)
    return repo_path
def get_head_branch(git_path, module, dest, remote, bare=False):