Remove test from commit fa2e874.

The fix itself is fine, but the test revealed other problems related
to parallel query that are not easily fixable. Remove the test for
now to fix the buildfarm.

Discussion: https://postgr.es/m/88825.1691665432@sss.pgh.pa.us
Backpatch-through: 11

Author: jeff-davis

src/test/isolation/expected/search-path-inval.out

@@ -110,4 +110,3 @@ test: serializable-parallel
 test: serializable-parallel-2
 test: serializable-parallel-3
 test: matview-write-skew
-test: search-path-inval