[MLIR] Omit version comment by default

[rsetaluri]

This change avoids having to update the version comment in gold files for every CIRCT upgrade.

[codecov-commenter]

Codecov Report

Patch coverage: 100.00% and no project coverage change.

Comparison is base (4592ee0) 85.93% compared to head (1d747f5) 85.94%.

❗ Current head 1d747f5 differs from pull request most recent head 6319723. Consider uploading reports for the commit 6319723 to get more accurate results

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Additional details and impacted files

@@           Coverage Diff           @@
##           master    #1313   +/-   ##
=======================================
  Coverage   85.93%   85.94%           
=======================================
  Files         169      169           
  Lines       17727    17727           
=======================================
+ Hits        15234    15235    +1     
+ Misses       2493     2492    -1     

Files Changed	Coverage Δ
magma/backend/mlir/compile_to_mlir_opts.py	100.00% <100.00%> (ø)

... and 1 file with indirect coverage changes

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