Upload coverage from all test runs

[solnic]

According to Codecov docs, merging reports works automatically (https://docs.codecov.com/docs/merging-reports) which means that if we just send multiple reports from all test runs, it'll merge them all. This PR shows that the coverage increased, so I guess it works?

#skip-changelog

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 98.97%. Comparing base (d134d9e) to head (5e36ec7).
Report is 1 commits behind head on master.

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #2430      +/-   ##
==========================================
+ Coverage   98.70%   98.97%   +0.26%     
==========================================
  Files         221      231      +10     
  Lines       14508    15094     +586     
==========================================
+ Hits        14320    14939     +619     
+ Misses        188      155      -33     

Components	Coverage Δ
sentry-ruby	99.14% <ø> (+0.12%)	⬆️
sentry-rails	98.46% <ø> (+1.02%)	⬆️
sentry-sidekiq	98.67% <ø> (+1.09%)	⬆️
sentry-resque	96.85% <ø> (-0.27%)	⬇️
sentry-delayed_job	98.92% <ø> (ø)
sentry-opentelemetry	99.75% <ø> (-0.25%)	⬇️

see 113 files with indirect coverage changes

[sl0thentr0py]

we need to do this for all the _test workflow files

[solnic]

@sl0thentr0py I had to fix some CI issues like bundler cache or fail-fast causing pre-mature job cancellations first via #2432 so please take a look there first :)

[solnic]

we need to do this for all the _test workflow files

@sl0thentr0py doooooone, had a lot of weird issues with bundling delayed_job ending up with:

rake aborted!
ArgumentError: wrong number of arguments (given 3, expected 2)
/home/runner/work/sentry-ruby/sentry-ruby/vendor/bundle/jruby/3.1.0/bundler/gems/activerecord-jdbc-adapter-6b3983bbbfda/Rakefile:355:in
`block in <main>'
/home/runner/work/sentry-ruby/sentry-ruby/vendor/bundle/jruby/3.1.0/bundler/gems/activerecord-jdbc-adapter-6b3983bbbfda/Rakefile:300:in
`block in <main>'
org/jruby/ext/monitor/Monitor.java:82:in `synchronize'
org/jruby/ext/monitor/Monitor.java:82:in `synchronize'
org/jruby/ext/monitor/Monitor.java:82:in `synchronize'
/home/runner/work/sentry-ruby/sentry-ruby/vendor/bundle/jruby/3.1.0/gems/rake-12.3.3/exe/rake:27:in

but after clearing bundle cache, it worked :)