Update changelog for both 3.5 and 3.6 for the PRs of trimming the suffix dot from target in SRV record

[ahrtr]

Update 3.5 changelog for PR pull/13714.

Previous changelog for 3.6 isn't accurate, so updated it as well in this PR.

A couple of generic/minor questions and comments:

1. All CHANGELOG files are only in the main branch. Does it mean that we need to remove the files from a newly cut release ranch? For example, when we cut release-3.6, then we need to remove all the CHANGELOG files from the branch release-3.6?
2. Each time when contributors backpot a fix to a previous version, then they need to submit a separate PR to update the CHANGELOG, because which exists only in the main branch. Obviously it's a little inconvenience.
3. I see some CHANGELOG items have a dot at the end, but some haven't. I think we need to follow the same rule. Just as I mentioned previously in another PR. If it's a complete sentence, then a dot is needed at the end, for example

etcd will no longer start on data dir created by newer versions (for example etcd v3.6 will not run on v3.7+ data dir). To downgrade data dir please check out `etcdutl migrate` command.

Otherwise, no need, for example,

Fix non mutating requests pass through quotaKVServer when NOSPACE  

cc @serathius @spzala @ptabor

[codecov-commenter]

Codecov Report

Merging #13720 (6781651) into main (a63fa17) will increase coverage by 0.11%.
The diff coverage is n/a.

@@            Coverage Diff             @@
##             main   #13720      +/-   ##
==========================================
+ Coverage   72.72%   72.83%   +0.11%     
==========================================
  Files         465      465              
  Lines       37886    37886              
==========================================
+ Hits        27552    27595      +43     
+ Misses       8548     8515      -33     
+ Partials     1786     1776      -10     

Flag	Coverage Δ
all	72.83% <ø> (+0.11%)	⬆️

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

Impacted Files	Coverage Δ
server/proxy/grpcproxy/register.go	69.76% <0.00%> (-9.31%)	⬇️
server/storage/mvcc/watchable_store.go	89.13% <0.00%> (-1.82%)	⬇️
server/etcdserver/server.go	85.08% <0.00%> (+0.23%)	⬆️
server/etcdserver/v3_server.go	79.01% <0.00%> (+0.35%)	⬆️
raft/node.go	87.55% <0.00%> (+0.85%)	⬆️
client/v3/retry_interceptor.go	64.54% <0.00%> (+0.90%)	⬆️
client/v3/leasing/kv.go	90.69% <0.00%> (+0.99%)	⬆️
server/lease/leasehttp/http.go	65.69% <0.00%> (+1.45%)	⬆️
server/etcdserver/api/v3rpc/watch.go	86.57% <0.00%> (+1.67%)	⬆️
pkg/traceutil/trace.go	98.07% <0.00%> (+1.92%)	⬆️
... and 7 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 a63fa17...6781651. Read the comment docs.