[CI] address sequence sampler test problem

[szha]

Description

address sequence sampler test failure

Checklist

Essentials

• PR's title starts with a category (e.g. [BUGFIX], [MODEL], [TUTORIAL], [FEATURE], [DOC], etc)
• Changes are complete (i.e. I finished coding on this PR)
• All changes have test coverage
• Code is well-documented

Changes

• Feature1, tests, (and when applicable, API doc)
• Feature2, tests, (and when applicable, API doc)

Comments

• If this change is a backward incompatible change, why must this change be made.
• Interesting edge cases to note here

[codecov]

Codecov Report

Merging #685 into master will increase coverage by 0.51%.
The diff coverage is n/a.

@@            Coverage Diff             @@
##           master     #685      +/-   ##
==========================================
+ Coverage   64.47%   64.99%   +0.51%     
==========================================
  Files         154      143      -11     
  Lines       14398    13117    -1281     
==========================================
- Hits         9283     8525     -758     
+ Misses       5115     4592     -523

Flag	Coverage Δ
#PR435	?
#PR466	?
#PR588	?
#PR612	?
#PR648	?
#PR663	?
#PR669	?
#PR672	?
#PR678	?
#PR685	64.99% <ø> (?)
#master	?
#notserial	41.54% <ø> (+2.7%)	⬆️
#py2	64.74% <ø> (-0.51%)	⬇️
#py3	64.87% <ø> (+0.53%)	⬆️
#serial	51.18% <ø> (ø)	⬆️

[codecov]

Codecov Report

Merging #685 into master will increase coverage by 0.54%.
The diff coverage is 100%.

@@            Coverage Diff             @@
##           master     #685      +/-   ##
==========================================
+ Coverage   64.47%   65.01%   +0.54%     
==========================================
  Files         154      143      -11     
  Lines       14398    13127    -1271     
==========================================
- Hits         9283     8535     -748     
+ Misses       5115     4592     -523

Flag	Coverage Δ
#PR435	?
#PR466	?
#PR588	?
#PR612	?
#PR648	?
#PR663	?
#PR669	?
#PR672	?
#PR678	?
#PR685	65.01% <100%> (?)
#master	?
#notserial	41.58% <66.66%> (+2.74%)	⬆️
#py2	64.77% <100%> (-0.49%)	⬇️
#py3	64.9% <100%> (+0.56%)	⬆️
#serial	51.2% <66.66%> (+0.01%)	⬆️

[mli]

Job PR-685/4 is complete.
Docs are uploaded to http://gluon-nlp-staging.s3-accelerate.dualstack.amazonaws.com/PR-685/4/index.html