providers/oauth2: optimize JWKS conversion (cherry-pick #24889 to version-2026.8)

[authentik-cherry-pick]

Cherry-pick of #24889 to version-2026.8 branch.

Original PR: #24889
Original Author: @BeryJu
Cherry-picked commit: d8733a5

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[codecov]

Codecov Report

❌ Patch coverage is 97.36842% with 1 line in your changes missing coverage. Please review.
✅ Project coverage is 91.37%. Comparing base (a1d716b) to head (90e1d8e).
✅ All tests successful. No failed tests found.

Files with missing lines	Patch %	Lines
authentik/providers/oauth2/views/jwks.py	97.36%	1 Missing ⚠️

Additional details and impacted files

@@               Coverage Diff               @@
##           version-2026.8   #24907   +/-   ##
===============================================
  Coverage           91.37%   91.37%           
===============================================
  Files                1137     1137           
  Lines               71571    71579    +8     
  Branches             3875     3875           
===============================================
+ Hits                65396    65406   +10     
+ Misses               6140     6138    -2     
  Partials               35       35           

Flag	Coverage Δ
conformance	34.84% <52.63%> (+<0.01%)	⬆️
e2e	39.56% <52.63%> (+<0.01%)	⬆️
integration	31.42% <13.15%> (+<0.01%)	⬆️
rust	38.89% <ø> (ø)
unit	93.03% <97.36%> (+<0.01%)	⬆️
unit-migrate	93.06% <97.36%> (+<0.01%)	⬆️

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[github-actions]

authentik PR Installation instructions

Instructions for docker-compose

Add the following block to your .env file:

AUTHENTIK_IMAGE=ghcr.io/goauthentik/dev-server
AUTHENTIK_TAG=gh-90e1d8ef0bb38e56d2c4e137dabb6cecd725c066
AUTHENTIK_OUTPOSTS__CONTAINER_IMAGE_BASE=ghcr.io/goauthentik/dev-%(type)s:gh-%(build_hash)s

Afterwards, run the upgrade commands from the latest release notes.

Instructions for Kubernetes

Add the following block to your values.yml file:

authentik:
    outposts:
        container_image_base: ghcr.io/goauthentik/dev-%(type)s:gh-%(build_hash)s
global:
    image:
        repository: ghcr.io/goauthentik/dev-server
        tag: gh-90e1d8ef0bb38e56d2c4e137dabb6cecd725c066

Afterwards, run the upgrade commands from the latest release notes.