[WIP Beyla 2.0]: moving some prom attributes to resource-level

[mariomac]

Moving the attributes to the target_info metric in Prometheus, so the Grafana dashboards, alerts, etc... should work the same independently of the exporter type.

[codecov-commenter]

Codecov Report

Attention: Patch coverage is 75.43860% with 14 lines in your changes missing coverage. Please review.

Project coverage is 75.83%. Comparing base (3464c37) to head (a923c1b).

Files	Patch %	Lines
pkg/internal/export/prom/prom.go	64.10%	13 Missing and 1 partial :warning:

:exclamation: There is a different number of reports uploaded between BASE (3464c37) and HEAD (a923c1b). Click for more details.

HEAD has 1 upload less than BASE

Flag	BASE (3464c37)	HEAD (a923c1b)
k8s-integration-test	1	0

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #1001      +/-   ##
==========================================
- Coverage   80.94%   75.83%   -5.11%     
==========================================
  Files         135      135              
  Lines       10725    10738      +13     
==========================================
- Hits         8681     8143     -538     
- Misses       1540     2089     +549     
- Partials      504      506       +2     

Flag	Coverage Δ
integration-test	55.85% <75.43%> (+0.06%)	:arrow_up:
k8s-integration-test	?
oats-test	36.24% <26.31%> (-0.10%)	:arrow_down:
unittests	50.79% <63.15%> (-0.07%)	:arrow_down:

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

:umbrella: View full report in Codecov by Sentry.
:loudspeaker: Have feedback on the report? Share it here.

[mariomac]

After discussing with @gouthamve, we will keep this on-hold, as might not be very convenient for some users that already count on resource attributes to be in prometheus metrics.

[mariomac]

Closing. We decided to not go on this way because what people really does at the end is to join the labels at the collector side.