[Dev] Some flaky testing cases might be improved

[jiangying000]

Here is a list of test cases prone to fail and requires retry to pass, I took them from CI log https://github.com/starcoinorg/starcoin/runs/8219047174

These test cases might be improved.

Especially, might be took as practices for developers interested at Rust from web3startrek

TRY 2 PASS [  46.448s]                starcoin-sync announcement::tests::test_get_txns_with_hash_from_pool
TRY 2 PASS [  52.323s]               starcoin-miner create_block_template::test_create_block_template::test_create_block_template
TRY 2 PASS [  43.588s]                starcoin-sync block_connector::test_illegal_block::test_verify_can_not_be_uncle_check_ancestor_failed
TRY 3 PASS [  47.544s]                 starcoin-cmd dev::tests::test_only_new_module
TRY 2 PASS [  41.306s]                starcoin-sync block_connector::test_illegal_block::test_verify_uncles_number_failed
TRY 2 PASS [  40.505s]                starcoin-sync block_connector::test_write_block_chain::test_block_chain_forks
TRY 3 PASS [  43.938s]             starcoin-genesis tests::test_builtin_genesis
TRY 2 PASS [  57.287s]                starcoin-sync tasks::tests::test_full_sync_fork_from_genesis
TRY 2 PASS [  59.289s]                starcoin-sync tasks::tests::test_full_sync_continue
TRY 2 PASS [  52.861s]                starcoin-sync tasks::tests::test_sync_target
TRY 2 PASS [ 100.693s]                starcoin-sync block_connector::test_illegal_block::test_verify_new_epoch_block_uncle_should_none_failed
TRY 2 PASS [ 102.740s]                starcoin-sync block_connector::test_illegal_block::test_verify_uncle_which_parent_is_end_block_in_last_epoch
TRY 2 PASS [ 104.390s]                starcoin-sync block_connector::test_illegal_block::test_verify_uncles_in_old_epoch_failed