Remove linting rule for list first/last

[marcotc]

This rule has been mostly ignored, since it doesn't always provide idiomatic Ruby.

Change log entry
No.

[datadog-datadog-prod-us1]

Datadog Report

Branch report: lint-first
Commit report: 080de1b
Test service: dd-trace-rb

✅ 0 Failed, 22065 Passed, 1477 Skipped, 5m 27.86s Total Time

[codecov-commenter]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 97.74%. Comparing base (9945a09) to head (080de1b).

Additional details and impacted files

@@           Coverage Diff           @@
##           master    #4364   +/-   ##
=======================================
  Coverage   97.74%   97.74%           
=======================================
  Files        1348     1348           
  Lines       82508    82508           
  Branches     4199     4199           
=======================================
+ Hits        80644    80649    +5     
+ Misses       1864     1859    -5     

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[pr-commenter]

Benchmarks

Benchmark execution time: 2025-02-11 09:35:06

Comparing candidate commit 080de1b in PR branch lint-first with baseline commit 9945a09 in branch master.

Found 2 performance improvements and 0 performance regressions! Performance is the same for 29 metrics, 2 unstable metrics.

scenario:profiler - sample timeline=false

• 🟩 throughput [+0.509op/s; +0.518op/s] or [+8.562%; +8.729%]

scenario:tracing - Propagation - Trace Context

• 🟩 throughput [+3539.127op/s; +3649.856op/s] or [+10.240%; +10.560%]