makefile: propagate `apidiff-compare` opts from callers

[dnaeon]

trafficstars

Description

The api-compatibility workflow sets custom options for apidiff as part of the Compare-States and Check-States steps here.

• https://github.com/open-telemetry/opentelemetry-collector/blob/6cd9c4e26feb910f19720950c8337af28194a70d/.github/workflows/api-compatibility.yml#L58
• https://github.com/open-telemetry/opentelemetry-collector/blob/6cd9c4e26feb910f19720950c8337af28194a70d/.github/workflows/api-compatibility.yml#L67

These opts are picked up by the Makefile and collected in the APICOMPARE_OPTS var here.

• https://github.com/open-telemetry/opentelemetry-collector/blob/6cd9c4e26feb910f19720950c8337af28194a70d/Makefile#L338-L343

However, these options are not propagated to apidiff when invoking the apidiff-compare target.

• https://github.com/open-telemetry/opentelemetry-collector/blob/6cd9c4e26feb910f19720950c8337af28194a70d/Makefile#L345-L348

This PR propagates the APICOMPARE_OPTS to the apidiff-compare target, so that any configured options (e.g. by workflows) are respected.

Link to tracking issue

None

Testing

Documentation