modify MALLOC_CONF for playground

[YangKeao]

Signed-off-by: YangKeao keao.yang@yahoo.com

In #1361, I forgot to modify the same environment variable for playground.

As discussed in tikv/tikv#10150, this option has brought some problems like tikv/tikv#10131 and other issues report (on asktug). And it could also cause performance regression or memory leaking (though, it seems not to be measuable).

[codecov-commenter]

Codecov Report

Merging #1369 (c3cf98a) into master (3202e61) will increase coverage by 4.62%.
The diff coverage is 100.00%.

❗ Current head c3cf98a differs from pull request most recent head c1784d7. Consider uploading reports for the commit c1784d7 to get more accurate results

@@            Coverage Diff             @@
##           master    #1369      +/-   ##
==========================================
+ Coverage   25.38%   30.00%   +4.62%     
==========================================
  Files         265      277      +12     
  Lines       20464    20887     +423     
==========================================
+ Hits         5194     6268    +1074     
+ Misses      14473    13650     -823     
- Partials      797      969     +172     

Flag	Coverage Δ
integrate	21.82% <100.00%> (+6.30%)	⬆️
playground	13.78% <100.00%> (?)
tiup	15.52% <ø> (ø)
unittest	21.68% <ø> (ø)

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

Impacted Files	Coverage Δ
components/playground/instance/tikv.go	67.34% <100.00%> (ø)
components/playground/instance/ticdc.go	0.00% <0.00%> (ø)
components/playground/instance/tiflash_config.go	100.00% <0.00%> (ø)
components/playground/instance/tidb.go	81.25% <0.00%> (ø)
components/playground/instance/process.go	81.39% <0.00%> (ø)
components/playground/instance/tiflash.go	59.09% <0.00%> (ø)
components/playground/instance/instance.go	45.45% <0.00%> (ø)
components/playground/instance/drainer.go	0.00% <0.00%> (ø)
...onents/playground/instance/tiflash_proxy_config.go	81.81% <0.00%> (ø)
... and 22 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 b3667bf...c1784d7. Read the comment docs.

[ti-chi-bot]

[REVIEW NOTIFICATION]

This pull request has been approved by:

• AstroProfundis

To complete the pull request process, please ask the reviewers in the list to review by filling /cc @reviewer in the comment.
After your PR has acquired the required number of LGTMs, you can assign this pull request to the committer in the list by filling /assign @committer in the comment to help you merge this pull request.

The full list of commands accepted by this bot can be found here.

Reviewer can indicate their review by writing /lgtm in a comment.
Reviewer can cancel approval by writing /lgtm cancel in a comment.

[AstroProfundis]

/merge

[ti-chi-bot]

This pull request has been accepted and is ready to merge.

Commit hash: c3cf98a