Use `TYPE_CHECKING` flag to avoid importing from `typing_extensions` at run time

[edgarrmondragon]

What do these changes do?

Use TYPE_CHECKING flag to avoid importing from typing_extensions at run time

Are there changes in behavior for the user?

typing_extensions would no longer be importable from this package, but users shouldn't be doing that anyway :)

Related issue number

https://github.com/aio-libs/aiodocker/issues/876

Checklist

• [x] I think the code is well written
• [ ] Unit tests for the changes exist
• [ ] Documentation reflects the changes
• [x] If you provide code modification, please add yourself to CONTRIBUTORS.txt
  • The format is <Name> <Surname>.
  • Please keep alphabetical order, the file is sorted by names.
• [x] Add a new news fragment into the changes folder
  • name it <issue_id>.<type> for example (588.bug)
  • if you don't have an issue_id change it to the pr id after creating the pr
  • ensure type is one of the following:
  • .feature: Signifying a new feature.
  • .bugfix: Signifying a bug fix.
  • .doc: Signifying a documentation improvement.
  • .removal: Signifying a deprecation or removal of public API.
  • .misc: A ticket has been closed, but it is not of interest to users.
  • Make sure to use full sentences with correct case and punctuation, for example: "Fix issue with non-ascii contents in doctest text files."

Closes https://github.com/aio-libs/aiodocker/issues/876

[edgarrmondragon]

FWIW it seems the pre-commit hook for mypy is missing a bunch of actual typing problems, but it's probably beyond the scope of this PR to fix those:

$ mypy aiodocker tests
aiodocker/stream.py:83: error: Item "None" of "ResponseHandler | None" has no attribute "transport"  [union-attr]
aiodocker/stream.py:83: error: Item "None" of "Transport | Any | None" has no attribute "get_extra_info"  [union-attr]
aiodocker/stream.py:90: error: Argument 1 to "FlowControlDataQueue" has incompatible type "ResponseHandler | None"; expected "BaseProtocol"  [arg-type]
aiodocker/stream.py:92: error: Item "None" of "ResponseHandler | None" has no attribute "set_parser"  [union-attr]
aiodocker/stream.py:93: error: Item "None" of "ResponseHandler | None" has no attribute "force_close"  [union-attr]
aiodocker/stream.py:94: error: Incompatible types in assignment (expression has type "FlowControlDataQueue[Message]", variable has type "None")  [assignment]
aiodocker/stream.py:111: error: Item "None" of "Connection | None" has no attribute "transport"  [union-attr]
aiodocker/stream.py:112: error: Item "None" of "Transport | Any | None" has no attribute "write"  [union-attr]
aiodocker/stream.py:113: error: Item "None" of "Connection | None" has no attribute "protocol"  [union-attr]
aiodocker/stream.py:114: error: Item "None" of "ResponseHandler | Any | None" has no attribute "transport"  [union-attr]
aiodocker/stream.py:115: error: Item "None" of "ResponseHandler | Any | None" has no attribute "_drain_helper"  [union-attr]
aiodocker/stream.py:123: error: Item "None" of "Connection | None" has no attribute "transport"  [union-attr]
aiodocker/logs.py:44: error: Incompatible types in assignment (expression has type "ClientResponse", variable has type "None")  [assignment]
aiodocker/docker.py:134: error: Argument "ssl" to "TCPConnector" has incompatible type "SSLContext | None"; expected "bool | Fingerprint | SSLContext"  [arg-type]
Found 14 errors in 3 files (checked 39 source files)