refactor(API): deprecate non-descriptor metric creation methods

[incertum]

Deprecates all metric creation methods that accept loose string parameters for name and help text.

This standardizes metric creation on the MetricNameDescriptor type, which requires a metricName, unitName and helpText for all metrics. This improves compliance with official Prometheus client library guidelines ("A MetricFamily MUST have a name, HELP, TYPE, and UNIT metadata.").

The deprecated methods will be removed in a future major version (see #145).

CC @ktoso, thank you!

[incertum]

Additional note: We should avoid redirecting to the public APIs that have now been marked as deprecated. I wanted to first ask for your opinion on this @ktoso . Happy to make these additional changes.

[incertum]

Additional note: We should avoid redirecting to the public APIs that have now been marked as deprecated. I wanted to first ask for your opinion on this @ktoso . Happy to make these additional changes.

I've pushed a suggestion.

[ktoso]

Looks good, AFAICS this keeps source compat

[incertum]

Please re re-review the latest minor fixes re CI failures, thanks! @FranzBusch @ktoso

[FranzBusch]

Can we avoid removing the warnings as errors setting? Are the deprecation warnings in the tests? If so you an mark the tests as deprecated which will silence those warnings.

[incertum]

Can we avoid removing the warnings as errors setting? Are the deprecation warnings in the tests? If so you an mark the tests as deprecated which will silence those warnings.

While it silenced it locally swift test -Xswiftc -warnings-as-errors 2 CI tests are now again erroring out.

[FranzBusch]

While it silenced it locally swift test -Xswiftc -warnings-as-errors 2 CI tests are now again erroring out.

It looks like only 5.10 and 6.0 are producing these warnings. Can we instead disable warnings-as-errors on just those versions. FWIW, we should also drop support for 5.10.

[incertum]

While it silenced it locally swift test -Xswiftc -warnings-as-errors 2 CI tests are now again erroring out.

It looks like only 5.10 and 6.0 are producing these warnings. Can we instead disable warnings-as-errors on just those versions. FWIW, we should also drop support for 5.10.

I have updated the override matrix (it wasn't yet configured for 6.0 and 6.1). It turns out that while having -Xswiftc -warnings-as-errors works on a macOS it appears just not to work the "same way" on these Linux runners.

I would propose to defer this and unblock this PR for now.

[incertum]

I'll go ahead and merge this. If we believe that additional refinements are beneficial, we can open a follow-up PR.