Drop Gem::Specification's usage so it doesn't break bundler standalone

[st0012]

Fixes #2329

I also needed to bump sqlite3 because v1.6.9 doesn't run on Ruby 3.3, which is what I use in development.

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 98.67%. Comparing base (069de02) to head (2f4e174).

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #2335      +/-   ##
==========================================
+ Coverage   98.66%   98.67%   +0.01%     
==========================================
  Files         205      205              
  Lines       13481    13479       -2     
==========================================
  Hits        13301    13301              
+ Misses        180      178       -2     

Components	Coverage Δ
sentry-ruby	99.04% <ø> (+0.01%)	⬆️
sentry-rails	97.41% <100.00%> (-0.01%)	⬇️
sentry-sidekiq	97.01% <ø> (ø)
sentry-resque	97.11% <ø> (+0.32%)	⬆️
sentry-delayed_job	98.92% <ø> (ø)
sentry-opentelemetry	100.00% <ø> (ø)

Files	Coverage Δ
...b/sentry/rails/tracing/active_record_subscriber.rb	90.19% <100.00%> (-0.37%)	⬇️

... and 2 files with indirect coverage changes

[st0012]

@sl0thentr0py working with older Rubies, especially those <= 2.5, has been increasingly frustrating. Is there any plan to ditch support for them?

[sl0thentr0py]

We can do it in the major, maybe I should do the major soon with dropping async and related stuff. The large hub refactor is postponed for now.

[st0012]

We can do it in the major, maybe I should do the major soon with dropping async and related stuff.

FWIW, dropping a dependency/language version isn't usually considered a breaking change because in that case, the user simply won't install that version onwards.

[sl0thentr0py]

I've had all kinds of problems in CI etc because someone dropped language support in a minor, just cleaner to do it in a major