### Summary

If a galaxy requirements file contains collections that have signatures defined, then `ansible-galaxy role install` with that requirements file fails because a keyring is not supplied.

### Issue Type

Bug Report

### Component Name

ansible-galaxy

### Ansible Version

```console
$ ansible --version

ansible [core 2.13.0.dev0] (devel ff184b0815) last updated 2022/03/24 16:21:31 (GMT -400)
  config file = /home/shrews/.ansible.cfg
  configured module search path = ['/home/shrews/.ansible/plugins/modules', '/usr/share/ansible/plugins/modules']
  ansible python module location = /home/shrews/Devel/github/Shrews/ansible/lib/ansible
  ansible collection location = /home/shrews/.ansible/collections:/usr/share/ansible/collections
  executable location = /home/shrews/Devel/github/Shrews/ansible/bin/ansible
  python version = 3.9.7 (default, Sep 10 2021, 14:59:43) [GCC 11.2.0]
  jinja version = 3.1.0
  libyaml = True
```


### Configuration

```console
$ ansible-config dump --only-changed

DEFAULT_HOST_LIST(/home/shrews/.ansible.cfg) = ['/home/shrews/Devel/ansible/hosts.yaml']
```


### OS / Environment

Ubuntu 21.10

### Steps to Reproduce

<!--- Paste example playbooks or commands between quotes below -->
```yaml (paste below)

$ cat req.yml 
collections:
  - name: community.mysql
    signatures:
      - file:///home/shrews/test.asc

$ ansible-galaxy role install -r req.yml 
ERROR! Signatures were provided to verify community.mysql but no keyring was configured.
```


### Expected Results

`role install` should ignore collection signatures

### Actual Results

```console
$ ansible-galaxy role install -r req.yml -vvvv

ansible-galaxy [core 2.13.0.dev0] (devel ff184b0815) last updated 2022/03/24 16:21:31 (GMT -400)
  config file = /home/shrews/.ansible.cfg
  configured module search path = ['/home/shrews/.ansible/plugins/modules', '/usr/share/ansible/plugins/modules']
  ansible python module location = /home/shrews/Devel/github/Shrews/ansible/lib/ansible
  ansible collection location = /home/shrews/.ansible/collections:/usr/share/ansible/collections
  executable location = /home/shrews/Devel/github/Shrews/ansible/bin/ansible-galaxy
  python version = 3.9.7 (default, Sep 10 2021, 14:59:43) [GCC 11.2.0]
  jinja version = 3.1.0
  libyaml = True
Using /home/shrews/.ansible.cfg as config file
Reading requirement file at '/home/shrews/req.yml'
ERROR! Signatures were provided to verify community.mysql but no keyring was configured.
```


### Code of Conduct

- [X] I agree to follow the Ansible Code of Conduct
cls,  
            dir_path,  
    ):  
        """Construct a collection instance based on an arbitrary dir.
        This alternative constructor infers the FQCN based on the parent
        and current directory names. It also sets the version to "*"
        regardless of whether any of known metadata files are present.
        """
        
        u_dir_path = to_text(dir_path, errors='surrogate_or_strict')
        path_list = u_dir_path.split(os.path.sep)
        req_name = '.'.join(path_list[-2:])
        return cls(req_name, '*', dir_path, 'dir', None)  
    @classmethod
    def from_string(cls, collection_input, artifacts_manager, supplemental_signatures):
        req = {}
        if _is_concrete_artifact_pointer(collection_input):
            
            req['name'] = collection_input
        else:
            req['name'], _sep, req['version'] = collection_input.partition(':')
            if not req['version']:
                del req['version']
        req['signatures'] = supplemental_signatures
        return cls.from_requirement_dict(req, artifacts_manager)
    @classmethod
    def from_requirement_dict(cls, collection_req, art_mgr):