pkg/util/coverage: update fakeTestDeps methods

Go 1.23 changed the signature of the testDeps interface so we need to
add a blank implementation for InitRuntimeCoverage to fakeTestDeps.

pkg/util/coverage/fake_test_deps.go

@@ -105,3 +105,8 @@ func (fakeTestDeps) ResetCoverage() {}
 
 //nolint:unused // U1000 see comment above, we know it's unused normally.
 func (fakeTestDeps) SnapshotCoverage() {}
+
+//nolint:unused // U1000 see comment above, we know it's unused normally.
+func (fakeTestDeps) InitRuntimeCoverage() (mode string, tearDown func(string, string) (string, error), snapcov func() float64) {
+	return "", nil, nil
+}