fix(cli): improve language selection logic in cliInit function

[ren-yamanashi]

Fixes #660

Description Changes

When running cdk init, if the specified command type can only be executed in a single language, allow the command to be executed without selecting a language.

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By submitting this pull request, I confirm that my contribution is made under the terms of the Apache-2.0 license

[iankhou]

Thanks for this. The original warning seemed to imply that if there was only one language, the command would work without specifying it. Good catch!

[codecov-commenter]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 80.91%. Comparing base (455c017) to head (ae14c54).
⚠️ Report is 2 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #806      +/-   ##
==========================================
- Coverage   81.46%   80.91%   -0.56%     
==========================================
  Files          63       63              
  Lines        8611     8618       +7     
  Branches     1039     1035       -4     
==========================================
- Hits         7015     6973      -42     
- Misses       1565     1616      +51     
+ Partials       31       29       -2     

Flag	Coverage Δ
suite.unit	80.91% <100.00%> (-0.56%)	⬇️

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