Add tracing to envtool tests run

[hungaikev]

Description

Adding tracing to envtool tests run

Closes #3665

Readiness checklist

• I added/updated unit tests (and they pass).
• I added/updated integration/compatibility tests (and they pass).
• I added/updated comments and checked rendering.
• I made spot refactorings.
• I updated user documentation.
• I ran task all, and it passed.
• I ensured that PR title is good enough for the changelog.
• (for maintainers only) I set Reviewers (@FerretDB/core), Milestone (Next), Labels, Project and project's Sprint fields.
• I marked all done items in this checklist.

[CLAassistant]

All committers have signed the CLA.

[codecov]

Codecov Report

Merging #3695 (df271fa) into main (504c567) will decrease coverage by 0.47%.
The diff coverage is 95.65%.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #3695      +/-   ##
==========================================
- Coverage   32.31%   31.85%   -0.47%     
==========================================
  Files         315      316       +1     
  Lines       23583    23586       +3     
==========================================
- Hits         7622     7514     -108     
- Misses      15277    15393     +116     
+ Partials      684      679       -5     

Files	Coverage Δ
internal/util/ctxutil/sigterm_unix.go	100.00% <100.00%> (ø)
internal/util/observability/observability.go	100.00% <100.00%> (ø)
internal/util/testutil/testutil.go	77.50% <100.00%> (ø)
integration/setup/startup.go	42.85% <50.00%> (-21.25%)	⬇️

... and 7 files with indirect coverage changes

Flag	Coverage Δ
filter-true	5.19% <95.65%> (-0.77%)	⬇️
hana-1	?
integration	5.19% <95.65%> (-0.77%)	⬇️
mongodb-1	5.19% <95.65%> (+0.01%)	⬆️
unit	30.77% <100.00%> (+0.05%)	⬆️

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

[AlekSi]

I don't see where this PR adds spans to envtool tests run command implementation in envtool.go. This issue is about adding tracing to it, not to its tests.

Please also run task all (or at least task fmt lint) locally.

[AlekSi]

That's not what needs to be done in that issue.

Let's use one trace per top-level test and spans for subtests

Not one span per go test invocation and one tracing event per decoded event. We need to start span when the decoded event indicates that the test started, end span when the test ends, handle paused and continued tests, etc.

[mergify]

@hungaikev this pull request has merge conflicts.

[AlekSi]

@hungaikev any news? Anything we could help you with?

[hungaikev]

@hungaikev any news? Anything we could help you with?

Hi @AlekSi would you be willing or available for a <= 15-minute block for us to go through this together to reduce the back and forth? I have a feeling that the part left is very small but seems to be taking 80% of the effort.

[AlekSi]

I fixed all the problems. The result looks like this:

[AlekSi]

@rumyantseva PTAL

[rumyantseva]

So, with the current approach, we can see when a particular event (run, continue, pause, pass) happened for each subtest. Looks good to me.