[MAINTENANCE] Remove docs_rtd

[joshua-stauffer]

This PR removes legacy docs code which is no longer used.

[netlify]

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[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 82.66%. Comparing base (8b36dc0) to head (519c777).

Additional details and impacted files

@@           Coverage Diff            @@
##           develop    #9737   +/-   ##
========================================
  Coverage    82.65%   82.66%           
========================================
  Files          512      512           
  Lines        46671    46671           
========================================
+ Hits         38578    38579    +1     
+ Misses        8093     8092    -1     

Flag	Coverage Δ
3.10	64.91% <ø> (ø)
3.11	64.91% <ø> (ø)
3.11 athena or clickhouse or openpyxl or pyarrow or project or sqlite or aws_creds	53.87% <ø> (ø)
3.11 aws_deps	48.96% <ø> (ø)
3.11 big	64.12% <ø> (ø)
3.11 databricks	48.14% <ø> (ø)
3.11 filesystem	63.80% <ø> (ø)
3.11 mssql	47.35% <ø> (ø)
3.11 mysql	47.40% <ø> (ø)
3.11 postgresql	54.16% <ø> (ø)
3.11 snowflake	48.67% <ø> (ø)
3.11 spark	60.57% <ø> (ø)
3.11 trino	53.80% <ø> (ø)
3.8	64.92% <ø> (ø)
3.8 athena or clickhouse or openpyxl or pyarrow or project or sqlite or aws_creds	53.88% <ø> (ø)
3.8 aws_deps	48.97% <ø> (ø)
3.8 big	64.13% <ø> (ø)
3.8 databricks	48.16% <ø> (ø)
3.8 filesystem	63.80% <ø> (ø)
3.8 mssql	47.33% <ø> (ø)
3.8 mysql	47.38% <ø> (ø)
3.8 postgresql	54.15% <ø> (ø)
3.8 snowflake	48.68% <ø> (-0.01%)	⬇️
3.8 spark	60.53% <ø> (ø)
3.8 trino	53.79% <ø> (ø)
3.9	64.91% <ø> (ø)
cloud	0.00% <ø> (ø)
docs-basic	54.44% <ø> (ø)
docs-creds-needed	55.01% <ø> (ø)
docs-spark	54.54% <ø> (ø)

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