fix(typing): make Response headers covariant

[Wurstnase]

Issue number: #3743

Summary

Changes

Change typing for headers in Response constructor.

User experience

Able to use covariant of dicts, e.g.

headers_with_str = {"str": "str"}
Response(200, headers=headers_with_str)

headers_with_list = {"str": "str", "list": ["1"]}
Response(200, headers=headers_with_list)

Checklist

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• Meet tenets criteria
• I have performed a self-review of this change
• Changes have been tested
• Changes are documented
• PR title follows conventional commit semantics

Is this a breaking change?

RFC issue number:

Checklist:

• Migration process documented
• Implement warnings (if it can live side by side)

Acknowledgment

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[boring-cyborg]

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[codecov-commenter]

Codecov Report

All modified and coverable lines are covered by tests ✅

Comparison is base (e14e768) 96.38% compared to head (cc7ff50) 96.38%.
Report is 21 commits behind head on develop.

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Additional details and impacted files

@@           Coverage Diff            @@
##           develop    #3745   +/-   ##
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  Coverage    96.38%   96.38%           
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  Files          214      214           
  Lines        10030    10030           
  Branches      1846     1846           
========================================
  Hits          9667     9667           
  Misses         259      259           
  Partials       104      104           

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[sonarcloud]

Quality Gate passed

Issues
0 New issues

Measures
0 Security Hotspots
No data about Coverage
0.0% Duplication on New Code

See analysis details on SonarCloud

[heitorlessa]

thank you @Wurstnase for this quick fix w/ Mapping generic. Everyone appreciates it :)

[boring-cyborg]

Awesome work, congrats on your first merged pull request and thank you for helping improve everyone's experience!