Instrument name limited to length of 62 instead of 255

[oeaoaueaa]

opentelemetry-dotnet/src/OpenTelemetry/Metrics/Builder/MeterProviderBuilderSdk.cs

Line 51 in 031ed48

@"^[a-z][a-z0-9-._]{0,62}$", RegexOptions.IgnoreCase | RegexOptions.Compiled);

Instrument name is being limited to a length of 62 but the specification cited in the comments says that the maximum length should be 255 and then a limit of 63 for the unit.

[cijothomas]

The spec just relaxed the limit from 63 to 255 couple of days back! It'd be good to get this relaxed in code as well.
@oeaoaueaa do you have interest/time to send a PR for the same?

[B3zaleel]

@cijothomas Could you please look at PR #4798 as it addresses this issue?