[Backport 2.x] Delete Spark datasource

[opensearch-trigger-bot[bot]]

Backport de7b367ec21f1eeba5698893fc713e86f783bdfb from #2638.

[codecov[bot]]

Codecov Report

All modified and coverable lines are covered by tests :white_check_mark:

Project coverage is 97.07%. Comparing base (294566f) to head (ed140e9).

Additional details and impacted files

@@             Coverage Diff              @@
##                2.x    #2642      +/-   ##
============================================
+ Coverage     95.42%   97.07%   +1.65%     
+ Complexity     5170     4587     -583     
============================================
  Files           491      403      -88     
  Lines         14598    12033    -2565     
  Branches        974      796     -178     
============================================
- Hits          13930    11681    -2249     
+ Misses          643      344     -299     
+ Partials         25        8      -17     

Flag	Coverage Δ
sql-engine	97.07% <ø> (+1.65%)	:arrow_up:

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[ykmr1224]

This backport will be addressed by #2667