perf: replace utils.json with orjson in tests

[anonrig]

Getting one step closer to removing sentry.utils.json

[codecov[bot]]

Codecov Report

Attention: Patch coverage is 84.44444% with 7 lines in your changes missing coverage. Please review.

Project coverage is 77.86%. Comparing base (d2ea815) to head (01cd7fe). Report is 987 commits behind head on master.

Additional details and impacted files

@@             Coverage Diff             @@
##           master   #71174       +/-   ##
===========================================
+ Coverage   61.11%   77.86%   +16.74%     
===========================================
  Files        6528     6530        +2     
  Lines      290848   290975      +127     
  Branches    50326    50359       +33     
===========================================
+ Hits       177748   226558    +48810     
+ Misses     107405    58185    -49220     
- Partials     5695     6232      +537     

Files	Coverage Δ
...try/api/endpoints/relocations/artifacts/details.py	91.48% <ø> (+41.48%)	:arrow_up:
src/sentry/issues/json_schemas.py	100.00% <100.00%> (+21.42%)	:arrow_up:
src/sentry/models/releasefile.py	95.25% <100.00%> (+37.32%)	:arrow_up:
src/sentry/seer/utils.py	93.19% <100.00%> (+35.66%)	:arrow_up:
src/sentry/tasks/relocation.py	88.76% <100.00%> (+43.37%)	:arrow_up:
src/sentry/utils/signing.py	100.00% <100.00%> (ø)
...sentry/hybridcloud/rpc/services/caching/service.py	94.66% <66.66%> (+2.56%)	:arrow_up:
src/sentry/backup/crypto.py	90.06% <50.00%> (-1.03%)	:arrow_down:
src/sentry/models/debugfile.py	72.26% <33.33%> (+43.13%)	:arrow_up:
src/sentry/utils/session_store.py	91.30% <80.00%> (+11.61%)	:arrow_up:

... and 1797 files with indirect coverage changes

[getsantry[bot]]

This pull request has gone three weeks without activity. In another week, I will close it.

But! If you comment or otherwise update it, I will reset the clock, and if you add the label WIP, I will leave it alone unless WIP is removed ... forever!

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"A weed is but an unloved flower." ― Ella Wheeler Wilcox 🥀