Handle empty frames case gracefully with local vars

[sl0thentr0py]

• resolves: Sentry capture_exception blows up on [] backtrace #2806
• resolves: RUBY-124

[linear]

RUBY-124 Sentry capture_exception blows up on `[]` backtrace

[sl0thentr0py]

sidekiq is failing because of mperham/connection_pool#210

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 90.11%. Comparing base (6c0ac11) to head (e79f595).
⚠️ Report is 1 commits behind head on master.

Additional details and impacted files

@@           Coverage Diff           @@
##           master    #2807   +/-   ##
=======================================
  Coverage   90.11%   90.11%           
=======================================
  Files         132      132           
  Lines        5299     5299           
=======================================
  Hits         4775     4775           
  Misses        524      524           

Components	Coverage Δ
sentry-ruby	97.26% <100.00%> (ø)
sentry-rails	55.40% <ø> (ø)
sentry-sidekiq	95.05% <ø> (ø)
sentry-resque	94.44% <ø> (ø)
sentry-delayed_job	94.68% <ø> (ø)
sentry-opentelemetry	99.31% <ø> (ø)

Files with missing lines	Coverage Δ
...try-ruby/lib/sentry/interfaces/single_exception.rb	97.43% <100.00%> (ø)

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.
• 📦 JS Bundle Analysis: Save yourself from yourself by tracking and limiting bundle sizes in JS merges.