tests: Make coins_tests/updatecoins_simulation_test deterministic

Summary:
Backport of core [[bitcoin/bitcoin#16225 | PR16225]].

Depends on D6620.

Test Plan:
  ninja check

Reviewers: #bitcoin_abc, deadalnix

Reviewed By: #bitcoin_abc, deadalnix

Differential Revision: https://reviews.bitcoinabc.org/D6621

src/test/coins_tests.cpp

@@ -292,6 +292,7 @@ UtxoData::iterator FindRandomFrom(const std::set<COutPoint> &utxoSet) {
 // overwritten at all cache levels)
 BOOST_AUTO_TEST_CASE(updatecoins_simulation_test) {
     SeedInsecureRand(/* deterministic */ true);
+    g_mock_deterministic_tests = true;
 
     bool spent_a_duplicate_coinbase = false;
     // A simple map to track what we expect the cache stack to represent.
@@ -505,6 +506,8 @@ BOOST_AUTO_TEST_CASE(updatecoins_simulation_test) {
 
     // Verify coverage.
     BOOST_CHECK(spent_a_duplicate_coinbase);
+
+    g_mock_deterministic_tests = false;
 }
 
 BOOST_AUTO_TEST_CASE(coin_serialization) {