[test] Delete old failing test

Test was already migrated to
pkg/vm_service/test/get_source_report_const_coverage_test.dart

Bug: #60522
Change-Id: I9094636c98d26fb2d3be5eeb873501c52a33d470
Fixes: #60522
TEST=CI
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/422280
Reviewed-by: Derek Xu <[email protected]>
Commit-Queue: Liam Appelbe <[email protected]>
Reviewed-by: Ben Konyi <[email protected]>

Author: liamappelbe