##### SUMMARY
If you have executable files in your source code they are not kept in the tarball.

Could be related to https://github.com/ansible/ansible/blob/99d7f150873011e7515851db9b44ff486efa9d77/lib/ansible/galaxy/collection.py#L763

This was noticed as I had some auxiliary scripts in my repo.

Need to also consider scripts in `files/` if/when Collections support roles.

This seems to fail the "principal of least suprise"

**Proposal 1: Keep on stripping executable flags**

Add some line to the output
`WARNING: tests/coverage.sh: source file has executable flag, though this will be ignored in generated tar.gz`
Update developing a collection documentation page
Update integration tests to ensure that executable mode is always stripped.
Update code to link to this issue

**Proposal 2: Allow executible flags**

Update developing a collection documentation page
Update integration tests to ensure that executable mode is preserved
Update code to link to this issue
Changelog


##### ISSUE TYPE
- Bug Report

##### COMPONENT NAME
ansible-galaxy

##### ANSIBLE VERSION
```paste below
2.10
```

##### STEPS TO REPRODUCE
<!--- Describe exactly how to reproduce the problem, using a minimal test-case -->

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

```

<!--- HINT: You can paste gist.github.com links for larger files -->


b_file_path = to_bytes(os.path.join(to_text(b_path), filename), errors='surrogate_or_strict')
        if not os.path.isfile(b_file_path):
            actual_hash = None
        else:
            with open(b_file_path, mode='rb') as file_object:
                actual_hash = _consume_file(file_object)
        if expected_hash != actual_hash:
            error_queue.append(ModifiedContent(filename=filename, expected=expected_hash, installed=actual_hash))
    def _get_metadata(self):
        if self._metadata:
            return
        self._metadata = self.api.get_collection_version_metadata(self.namespace, self.name, self.latest_version)
    def _meets_requirements(self, version, requirements, parent):
        """
        Supports version identifiers can be '==', '!=', '>', '>=', '<', '<=', '*'. Each requirement is delimited by ','
        """
        op_map = {
            '!=': operator.ne,
            '==': operator.eq,
            '=': operator.eq,
            '>=': operator.ge,
            '>': operator.gt,
            '<=': operator.le,
            '<': operator.lt,
        }
        for req in list(requirements.split(',')):
            op_pos = 2 if len(req) > 1 and req[1] == '=' else 1
            op = op_map.get(req[:op_pos])
            requirement = req[op_pos:]
            if not op: