[Span Metrics Connector] docs: add span metrics high cardinality troubleshooting docs

[cyrille-leclerc]

Description

Add documentation to help fix Span Metrics Connector's metrics high cardinality problems.

Note that @iblancasa and @Frapschen reviewed the PR to introduce the set_semconv_span_name() function #43145 , reviewing this documentation PR should be straightforward to them.

Link to tracking issue

None

Testing

N/A

Documentation

This is a documentation PR

[crobert-1]

LGTM. Documentation-only changes don't require changelogs, and I'd probably prefer it if we removed the entry. I can add a label to this PR to make sure CI still passes without it 👍

[cyrille-leclerc]

LGTM. Documentation-only changes don't require changelogs, and I'd probably prefer it if we removed the entry. I can add a label to this PR to make sure CI still passes without it 👍

I got the message No changelog entry was added to the ./.chloggen/ directory. ... Alternately, add either "[chore]" to the title of the pull request or add the "Skip Changelog" label if this job should be skipped.

Can you add the label "skip changelog"?

[crobert-1]

Can you add the label "skip changelog"?

I've added it. For future reference, the alternative is to add [chore] to the beginning of your PR's title (source). 👍