Prometheus scrape endpoint

[mariomac]

It also fixes the OTEL metrics units from milliseconds to seconds, to be consistent with the latest OpenTelemetry specification.

Most of the PR files are just vendored dependencies

[codecov-commenter]

Codecov Report

Merging #110 (23631c3) into main (94bcce3) will decrease coverage by 30.60%.
The diff coverage is 19.33%.

@@             Coverage Diff             @@
##             main     #110       +/-   ##
===========================================
- Coverage   75.38%   44.78%   -30.60%     
===========================================
  Files          21       22        +1     
  Lines        1503     1601       +98     
===========================================
- Hits         1133      717      -416     
- Misses        276      833      +557     
+ Partials       94       51       -43     

Flag	Coverage Δ
integration-test	?
unittests	44.78% <19.33%> (-3.28%)	⬇️

Flags with carried forward coverage won't be shown. Click here to find out more.

Impacted Files	Coverage Δ
pkg/ebpf/tracer.go	0.00% <0.00%> (-63.22%)	⬇️
pkg/pipe/config.go	53.33% <ø> (ø)
pkg/export/prom/prom.go	1.40% <1.40%> (ø)
pkg/export/otel/traces.go	78.85% <57.14%> (-0.88%)	⬇️
pkg/export/otel/metrics.go	70.88% <100.00%> (-8.45%)	⬇️
pkg/pipe/global/context.go	100.00% <100.00%> (ø)
pkg/pipe/instrumenter.go	82.14% <100.00%> (-8.49%)	⬇️
pkg/transform/spanner.go	80.95% <100.00%> (-2.39%)	⬇️

... and 12 files with indirect coverage changes

[grcevski]

LGTM! Amazing work!