fix: rename datasource->dataset in error message

[mistercrunch]

Looks like we missed that one on wider renaming effort.

[codecov]

Codecov Report

Merging #21959 (546d2a1) into master (7e3e133) will increase coverage by 0.00%.
The diff coverage is n/a.

@@           Coverage Diff           @@
##           master   #21959   +/-   ##
=======================================
  Coverage   66.94%   66.95%           
=======================================
  Files        1807     1807           
  Lines       69210    69210           
  Branches     7399     7399           
=======================================
+ Hits        46335    46338    +3     
+ Misses      20966    20963    -3     
  Partials     1909     1909           

Flag	Coverage Δ
hive	52.92% <ø> (ø)
mysql	78.36% <ø> (ø)
postgres	78.43% <ø> (+<0.01%)	⬆️
presto	52.82% <ø> (ø)
python	81.48% <ø> (+<0.01%)	⬆️
sqlite	76.91% <ø> (ø)
unit	51.09% <ø> (ø)

Flags with carried forward coverage won't be shown. Click here to find out more.

Impacted Files	Coverage Δ
superset/common/query_context_processor.py	88.51% <ø> (ø)
superset/common/query_object.py	94.38% <0.00%> (+0.51%)	⬆️
superset/commands/importers/v1/utils.py	93.50% <0.00%> (+1.29%)	⬆️
superset/reports/commands/log_prune.py	89.28% <0.00%> (+3.57%)	⬆️

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[zhaoyongjie]

LGTM