chore: remove unused variable

[hiixfj]

• What kind of change does this PR introduce? (Bug fix, feature, docs update, ...)
  cleanup, close Remove unused variable #1746

• What is the current behavior? (You can also link to an open issue here)

• What is the new behavior (if this is a feature change)?

[github-actions]

SDK Test Report

  73 files    73 suites   6m 0s ⏱️
174 tests 171 ✔️ 3 💤 0 ❌
215 runs  212 ✔️ 3 💤 0 ❌

Results for commit 903fa8f.

[github-actions]

HybridSE Linux Test Report

       67 files       235 suites   5m 41s ⏱️
19 003 tests 19 001 ✔️ 2 💤 0 ❌

Results for commit 903fa8f.

[github-actions]

HybridSE Mac Test Report

       67 files       235 suites   6m 56s ⏱️
19 003 tests 19 001 ✔️ 2 💤 0 ❌

Results for commit 903fa8f.

[github-actions]

Linux Test Report

       57 files       186 suites   1h 6m 39s ⏱️
  8 468 tests   8 460 ✔️ 8 💤 0 ❌
12 419 runs  12 411 ✔️ 8 💤 0 ❌

Results for commit 903fa8f.

[codecov]

Codecov Report

Merging #1766 (903fa8f) into main (76183cf) will decrease coverage by 0.00%.
The diff coverage is n/a.

@@             Coverage Diff              @@
##               main    #1766      +/-   ##
============================================
- Coverage     73.66%   73.66%   -0.01%     
  Complexity      347      347              
============================================
  Files           614      614              
  Lines        120132   120131       -1     
  Branches       1015     1015              
============================================
- Hits          88499    88491       -8     
- Misses        31424    31431       +7     
  Partials        209      209              

Impacted Files	Coverage Δ
hybridse/src/codegen/udf_ir_builder.cc	82.92% <ø> (-0.06%)	⬇️
...s/query_response_time/deploy_query_response_time.h	81.25% <0.00%> (-18.75%)	⬇️
...atistics/query_response_time/query_response_time.h	78.26% <0.00%> (-4.35%)	⬇️
.../query_response_time/deploy_query_response_time.cc	97.10% <0.00%> (-2.90%)	⬇️
src/sdk/sql_cluster_router.cc	54.41% <0.00%> (-0.18%)	⬇️
src/storage/mem_table.cc	89.13% <0.00%> (-0.14%)	⬇️
src/nameserver/name_server_impl.cc	42.23% <0.00%> (-0.13%)	⬇️
src/tablet/tablet_impl.cc	58.86% <0.00%> (-0.13%)	⬇️
src/client/tablet_client.cc	48.50% <0.00%> (+0.20%)	⬆️
src/rpc/rpc_client.h	90.54% <0.00%> (+1.35%)	⬆️
... and 2 more

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update 76183cf...903fa8f. Read the comment docs.