tests/integration: re-enable TestV3AuthOldRevConcurrent

[mitake]

#10468 and #13308 fixed the issue of TestV3AuthOldRevConcurrent. We can re-enable the test.
cc @endocrimes @jingyih

Fix #13805

[codecov-commenter]

Codecov Report

Merging #13828 (7a0c254) into main (4787e71) will decrease coverage by 0.08%.
The diff coverage is n/a.

@@            Coverage Diff             @@
##             main   #13828      +/-   ##
==========================================
- Coverage   72.56%   72.47%   -0.09%     
==========================================
  Files         467      467              
  Lines       38280    38280              
==========================================
- Hits        27777    27745      -32     
- Misses       8720     8748      +28     
- Partials     1783     1787       +4     

Flag	Coverage Δ
all	72.47% <ø> (-0.09%)	⬇️

Flags with carried forward coverage won't be shown. Click here to find out more.

Impacted Files	Coverage Δ
client/pkg/v3/tlsutil/tlsutil.go	83.33% <0.00%> (-8.34%)	⬇️
raft/rafttest/node.go	95.00% <0.00%> (-5.00%)	⬇️
client/v3/concurrency/session.go	88.63% <0.00%> (-4.55%)	⬇️
server/storage/mvcc/watchable_store.go	84.42% <0.00%> (-4.35%)	⬇️
client/v3/leasing/cache.go	87.77% <0.00%> (-3.89%)	⬇️
server/etcdserver/util.go	85.71% <0.00%> (-3.18%)	⬇️
server/etcdserver/api/v3election/election.go	66.66% <0.00%> (-2.78%)	⬇️
client/v3/concurrency/election.go	79.68% <0.00%> (-2.35%)	⬇️
pkg/traceutil/trace.go	96.15% <0.00%> (-1.93%)	⬇️
client/v3/watch.go	92.16% <0.00%> (-1.41%)	⬇️
... and 9 more

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