feat: drop support for Python 3.8

[bellini666]

Python 3.8 has reached EOL a couple of months ago, it's time to drop support for it.

https://devguide.python.org/versions/

[sourcery-ai]

The pull request #3730 has too many files changed.

We can only review pull requests with up to 300 changed files, and this pull request has 303.

[botberry]

Apollo Federation Subgraph Compatibility Results

Federation 1 Support	Federation 2 Support
_service 🟢 @key (single) 🟢 @key (multi) 🟢 @key (composite) 🟢 repeatable @key 🟢 @requires 🟢 @provides 🟢 federated tracing 🔲	@link 🟢 @shareable 🟢 @tag 🟢 @override 🟢 @inaccessible 🟢 @composeDirective 🟢 @interfaceObject 🟢

Learn more:

• Apollo Federation Subgraph Specification
• Compatibility Tests

[botberry]

Thanks for adding the RELEASE.md file!

Here's a preview of the changelog:

---

This release drops support for Python 3.8, which reached its end-of-life (EOL)
in October 2024. The minimum supported Python version is now 3.9.

We strongly recommend upgrading to Python 3.9 or a newer version, as older
versions are no longer maintained and may contain security vulnerabilities.

Here's the tweet text:

🆕 Release (next) is out! Thanks to @_bellini666 for the PR 👏

Get it here 👉 https://strawberry.rocks/release/(next)

[codecov]

Codecov Report

Attention: Patch coverage is 99.57717% with 4 lines in your changes missing coverage. Please review.

Project coverage is 97.12%. Comparing base (0981661) to head (f5e224d).
Report is 1 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #3730      +/-   ##
==========================================
+ Coverage   96.97%   97.12%   +0.14%     
==========================================
  Files         504      503       -1     
  Lines       33768    33524     -244     
  Branches     5639     5507     -132     
==========================================
- Hits        32748    32561     -187     
+ Misses        810      756      -54     
+ Partials      210      207       -3     

[codspeed-hq]

CodSpeed Performance Report

Merging #3730 will not alter performance

_{Comparing py39 (f5e224d) with main (0981661)}

Summary

✅ 21 untouched benchmarks