[metric spec review] Incorrect API tsdoc Inputs MAY/MUST not be negative

[dyladan]

    Nit: not part of the spec compliance review but I noticed this comment:

opentelemetry-js/api/src/metrics/Metric.ts

Line 67 in d154066

* Increment value of counter by the input. Inputs may not be negative.

Do we want Inputs may not be negative. or Inputs must not be negative.? (if we look at histogram, it is using the must wording

opentelemetry-js/api/src/metrics/Metric.ts

Line 81 in d154066

* Records a measurement. Value of the measurement must not be negative.

)

Originally posted by @reyang in open-telemetry/community#1204 (comment)

[legendecas]

Quick fix: #3396