*: upgrade etcd to v3.4.3 (#2058)

[nolouch]

Signed-off-by: nolouch nolouch@gmail.com

What problem does this PR solve?

Update etcd to v3.4.3.
Fix:

• fix mvcc: revert change made by #10526 and #10699 etcd-io/etcd#10772

What is changed and how it works?

update release-3.1

Check List

Tests

• Unit test
• Integration test

[codecov-io]

Codecov Report

Merging #2063 into release-3.1 will increase coverage by 0.13%.
The diff coverage is 100%.

@@               Coverage Diff               @@
##           release-3.1    #2063      +/-   ##
===============================================
+ Coverage        69.52%   69.65%   +0.13%     
===============================================
  Files              171      171              
  Lines            16846    16846              
===============================================
+ Hits             11712    11734      +22     
+ Misses            4155     4136      -19     
+ Partials           979      976       -3

Impacted Files	Coverage Δ
pkg/metricutil/metricutil.go	86.11% <100%> (ø)	⬆️
server/api/utiletcdhttpapi.go	55.55% <0%> (-22.23%)	⬇️
server/api/diagnose.go	60.34% <0%> (-5.18%)	⬇️
server/grpc_service.go	58.63% <0%> (-2.35%)	⬇️
client/client.go	74.53% <0%> (-0.83%)	⬇️
server/handler.go	51.98% <0%> (+0.49%)	⬆️
server/cluster.go	81.81% <0%> (+0.5%)	⬆️
server/schedule/operator.go	87.58% <0%> (+0.64%)	⬆️
server/statistics/store_collection.go	86.95% <0%> (+1.44%)	⬆️
server/statistics/region_collection.go	91.24% <0%> (+1.45%)	⬆️
... and 7 more

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[nolouch]

/run-all-tests

[HunDunDM]

LGTM.

[lhy1024]

/merge

[nolouch]

/merge

[sre-bot]

/run-all-tests