##### 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 -->


from collections import namedtuple
from contextlib import contextmanager
from distutils.version import LooseVersion
from hashlib import sha256
from io import BytesIO
from yaml.error import YAMLError
try:
    import queue
except ImportError:
    import Queue as queue  
import ansible.constants as C
from ansible.errors import AnsibleError
from ansible.galaxy import get_collections_galaxy_meta_info
from ansible.galaxy.api import CollectionVersionMetadata, GalaxyError
from ansible.galaxy.user_agent import user_agent
from ansible.module_utils import six
from ansible.module_utils._text import to_bytes, to_native, to_text
from ansible.utils.collection_loader import AnsibleCollectionRef
from ansible.utils.display import Display
from ansible.utils.hashing import secure_hash, secure_hash_s
from ansible.utils.version import SemanticVersion
from ansible.module_utils.urls import open_url
urlparse = six.moves.urllib.parse.urlparse
urllib_error = six.moves.urllib.error
display = Display()
MANIFEST_FORMAT = 1
ModifiedContent = namedtuple('ModifiedContent', ['filename', 'expected', 'installed'])
class CollectionRequirement:
    _FILE_MAPPING = [(b'MANIFEST.json', 'manifest_file'), (b'FILES.json', 'files_file')]
    def __init__(self, namespace, name, b_path, api, versions, requirement, force, parent=None, metadata=None,