Remove TransactionHolder.java

[tuichenchuxin]

for #20005

Changes proposed in this pull request:

• remove TransactionHolder.java

[codecov-commenter]

Codecov Report

Merging #20184 (a46cde9) into master (466002c) will decrease coverage by 0.01%.
The diff coverage is 75.00%.

@@             Coverage Diff              @@
##             master   #20184      +/-   ##
============================================
- Coverage     60.97%   60.96%   -0.02%     
  Complexity     2418     2418              
============================================
  Files          3873     3873              
  Lines         54428    54426       -2     
  Branches       7623     7623              
============================================
- Hits          33187    33180       -7     
- Misses        18381    18386       +5     
  Partials       2860     2860              

Impacted Files	Coverage Δ
.../dbdiscovery/route/DatabaseDiscoverySQLRouter.java	95.23% <ø> (ø)
...nce/FixedPrimaryReadQueryLoadBalanceAlgorithm.java	60.00% <ø> (ø)
...ransactionRandomReadQueryLoadBalanceAlgorithm.java	66.66% <ø> (ø)
...actionRoundRobinReadQueryLoadBalanceAlgorithm.java	66.66% <ø> (ø)
...ransactionWeightReadQueryLoadBalanceAlgorithm.java	69.38% <ø> (ø)
...e/shardingsphere/shadow/route/ShadowSQLRouter.java	33.33% <ø> (ø)
...phere/sharding/route/engine/ShardingSQLRouter.java	78.94% <ø> (ø)
...hardingsphere/infra/session/ConnectionContext.java	0.00% <0.00%> (ø)
...sion/transaction/TransactionConnectionContext.java	0.00% <0.00%> (ø)
...e/infra/route/engine/impl/AllSQLRouteExecutor.java	100.00% <ø> (ø)
... and 17 more

📣 We’re building smart automated test selection to slash your CI/CD build times. Learn more