fix: Switch Redocly build to use standalone html file

[tirumerla]

Summary

• Instead of redocly build and injecting nonces in docs.openzeppelin.com, this pr fixes that approach by using standalone html and referring openapi file

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 88.4%. Comparing base (7b5372b) to head (b14de9b).
⚠️ Report is 5 commits behind head on main.

Additional details and impacted files

@@          Coverage Diff          @@
##            main    #291   +/-   ##
=====================================
  Coverage   88.4%   88.4%           
=====================================
  Files        210     210           
  Lines      67457   67457           
=====================================
+ Hits       59661   59663    +2     
+ Misses      7796    7794    -2     

Flag	Coverage Δ
integration	0.5% <ø> (ø)
properties	<0.1% <ø> (ø)
unittests	91.8% <ø> (+<0.1%)	⬆️

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