Prevent memory exhaustion when generating TIA graphs with PCOV (#1875)

* fix(tia): preserve memory limit during pcov restart

* chore: update test expectations

* fix: stabilize tia replay test in ci

tests/Features/Tia.php

@@ -56,6 +56,7 @@ it('does not run user hooks when replaying cached skipped and incomplete results
                 'PARATEST' => 0,
                 'PAO_DISABLE' => '1',
                 'HOME' => $home,
+                'CI_DEFAULT_BRANCH' => $branch,
             ],
         );