[summarize-checks] label `RPaaSException` cannot be used to override label `CI-NewRPNamespaceWithoutRPaaS`

[mikeharder]

This PR got labeled with CI-NewRPNamespaceWithoutRPaaS (correctly):

#37814 (comment)

However, when the ARM reviewer attempted to override using label RPaaSException, our automation immediately removed the label:

Instead, I believe the expected behavior is to leave label RPaaSException alone, and to have it override CI-NewRPNamespaceWithoutRPaaS to unblock the PR. This code looks correct:

azure-rest-api-specs/.github/workflows/src/summarize-checks/labelling.js

Lines 864 to 869 in 2caaf9e

	{
	precedence: 0,
	allPrerequisiteLabels: ["NotReadyForARMReview", "CI-NewRPNamespaceWithoutRPaaS"],
	anyRequiredLabels: ["RPaaSException"],
	troubleshootingGuide: notReadyForArmReviewReason("CI-NewRPNamespaceWithoutRPaaS"),
	},

However, some other code must be earlier determining that RPaaSException should be removed.

This run of summarize-checks removed the label:

https://github.com/Azure/azure-rest-api-specs/actions/runs/18144101186/job/51641822826#step:4:74

I think the bug may be related to confusion between the label RPaaSException, and property rpaasExceptionRequired in the impact assessment.

ImpactAssessment: {
"suppressionReviewRequired":true,
"rpaasChange":false,
"newRP":true,
"rpaasRPMissing":true,
"rpaasRpNotInPrivateRepo":false,
"resourceManagerRequired":true,
"dataPlaneRequired":false,
"rpaasExceptionRequired":false,
"typeSpecChanged":false,
"isNewApiVersion":true,
"isDraft":false,
"targetBranch":"main"
}