Disallow creating new sessions if client exits context

[cepedus]

Description of Change

Once an AioBaseClient is used as a context manager and exits, forbid any following attempt to create a new session.

If AioBaseClient is never used as a context manager, this restriction does not apply.

Assumptions

Checklist for All Submissions

• I have added change info to CHANGES.rst
• If this is resolving an issue (needed so future developers can determine if change is still necessary and under what conditions) (can be provided via link to issue with these details): Closed client can create non-contextualized connections #1398
  • Detailed description of issue
  • Alternative methods considered (if any)
  • How issue is being resolved
  • How issue can be reproduced
• If this is providing a new feature (can be provided via link to issue with these details):
  • Detailed description of new feature
  • Why needed
  • Alternatives methods considered (if any)

Checklist when updating botocore and/or aiohttp versions

(not applicable)

• I have read and followed CONTRIBUTING.rst
• I have updated test_patches.py where/if appropriate (also check if no changes necessary)
• I have ensured that the awscli/boto3 versions match the updated botocore version
• I have added URL to diff: boto/botocore@[CURRENT_BOTO_VERSION_TAG]...[NEW_BOTO_VERSION_TAG]

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 91.58%. Comparing base (0dd027c) to head (1c52a86).

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #1402      +/-   ##
==========================================
+ Coverage   91.39%   91.58%   +0.18%     
==========================================
  Files          74       74              
  Lines        7855     7864       +9     
==========================================
+ Hits         7179     7202      +23     
+ Misses        676      662      -14     

Flag	Coverage Δ
no-httpx	90.02% <100.00%> (+0.04%)	⬆️
os-ubuntu-24.04	91.50% <100.00%> (+0.11%)	⬆️
os-ubuntu-24.04-arm	91.32% <100.00%> (+0.18%)	⬆️
python-3.10	91.15% <100.00%> (+0.04%)	⬆️
python-3.11	91.22% <100.00%> (+0.11%)	⬆️
python-3.12	91.22% <100.00%> (+0.11%)	⬆️
python-3.13	91.15% <100.00%> (+0.04%)	⬆️
python-3.14	91.48% <100.00%> (+0.12%)	⬆️
python-3.9	91.24% <100.00%> (+0.12%)	⬆️
unittests	91.58% <100.00%> (+0.18%)	⬆️

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[thehesiod]

@cepedus you'll need to sign and force push the commits

[jakob-keller]

As I understand it, this PR enforces using AIOHTTPSession as an asynchronous context manager, which was strongly recommended, but optional before. IMO, this might need to be considered a breaking change. Any thoughts? Why is the current situation problematic again?

[cepedus]

@jakob-keller The current behavior is prone to loose sessions that are potentially never closed in the default use-case (RuntimeError potential down the stream if the loop is closed). I agree this could mean a breaking change to those users, which version should I put then?

@thehesiod I signed all commmits, review was dismissed though

[cepedus]

Up, should I continue this MR?

[thehesiod]

@cepedus sorry about delay, been sick. Lets do a major bump to obey semver rules, and merge this puppy

[cepedus]

Bumped major + updated branch :)