Do not fail mergeTestReports for partial previous test task runs

[jdaugherty]

If a user:

1. runs integrationTest - and it's terminated (OOM, etc) before finish
2. then runs smokeTest

The mergeTestReports will fail b/c it's partially run, an error like this will show:

  Caused by: java.lang.IllegalStateException: Test outputs data file '$PROJECT_DIR/build/test-results/gebTest/binary/output.bin' exists but the index file '$PROJECT_DIR/build/test-results/gebTest/binary/output.bin.idx' does not
    at org.gradle.api.internal.tasks.testing.junit.result.TestOutputStore$Reader.<init>(TestOutputStore.java:231)
    at org.gradle.api.internal.tasks.testing.junit.result.TestOutputStore.reader(TestOutputStore.java:391)
    at org.gradle.api.internal.tasks.testing.junit.result.TestOutputStoreBackedResultsProvider.<init>(TestOutputStoreBackedResultsProvider.java:28)
    at org.gradle.api.internal.tasks.testing.junit.result.BinaryResultBackedTestResultsProvider.<init>(BinaryResultBackedTestResultsProvider.java:27)
    at org.gradle.util.internal.CollectionUtils.collect(CollectionUtils.java:192)
    at org.gradle.api.internal.tasks.testing.LegacyTestReportGenerator.lambda$createAggregateProvider$1(LegacyTestReportGenerator.java:54)
    at org.gradle.api.internal.tasks.testing.LegacyTestReportGenerator.hasResults(LegacyTestReportGenerator.java:71)
    at org.gradle.api.tasks.testing.TestReport.generateReport(TestReport.java:186)
    ... 125 more

This is because the index file isn't generated until after the task finishes. This PR simply removes these invalid states so the test report task doesn't fail.

[testlens-app]

✅ All tests passed ✅

🏷️ Commit: 46e57a1
▶️ Tests: 5162 executed
⚪️ Checks: 35/35 completed

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[jdaugherty]

FYI: This may be a regression with 7.1. There was a swallowed exception I noticed while working on this change because these views didn't exist in this project. It may be related to Scott's wildcard mapping change. Although, I think it doesn't have a real impact so it's probably ok.

[bito-code-review]

The change removes URL mappings to views ('/index', '/error', '/notFound') that don't exist in the project, which were causing swallowed exceptions in Grails 7.1, likely due to wildcard mapping updates. Removing them prevents errors without impact, as these are default fallbacks. This appears to be a valid fix for the regression.

grails-test-examples/test-phases/grails-app/controllers/testphases/UrlMappings.groovy

'/'(view: '/index')
        '500'(view: '/error')
        '404'(view: '/notFound')