fix(instrumentation-pino): log-sending was losing records when the level was reduced

[trentm]

Before this fix, if a Pino logger level was reduced (e.g. from 'info' to 'debug'),
then log.debug('msg') would not work. The same thing would happen if a child
logger was created at a lower-level than its parent.

This issue was that PinoInstrumentation is internally using a pino multistream
(https://getpino.io/#/docs/api?id=pino-multistream) and statically setting
the level of those streams to the current Logger level. If the logger level
was set lower, the multistream levels would end up filtering records
at that original higher level. The fix is to set the stream levels to
0 to never filter out records.

Closes: #2696

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 90.96%. Comparing base (0057f15) to head (d5a577a).
Report is 1 commits behind head on main.

Additional details and impacted files

@@           Coverage Diff           @@
##             main    #2699   +/-   ##
=======================================
  Coverage   90.96%   90.96%           
=======================================
  Files         171      171           
  Lines        8133     8133           
  Branches     1649     1649           
=======================================
  Hits         7398     7398           
  Misses        735      735           

Files with missing lines	Coverage Δ
...emetry-instrumentation-pino/src/instrumentation.ts	100.00% <ø> (ø)

[trentm]

Cycle the instr-pino label to see if that triggers the TAV test run.