Add create index check for ScaNN and fix UTs

[chasingegg]

Currently we have cpu check for ScaNN when building index/searching, we could also check while creating index and stop early for those old cpu models.
Also, check cpu model in UTs.

/kind improvement

[sre-ci-robot]

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[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 72.15%. Comparing base (3c46f4c) to head (73e5540).
Report is 173 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff            @@
##           main     #816       +/-   ##
=========================================
+ Coverage      0   72.15%   +72.15%     
=========================================
  Files         0       84       +84     
  Lines         0     6126     +6126     
=========================================
+ Hits          0     4420     +4420     
- Misses        0     1706     +1706     

see 84 files with indirect coverage changes

[cqy123456]

/lgtm