pgsql: Remove test from commit fa2e874946.

Remove test from commit fa2e874946.

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

Branch
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REL_14_STABLE

Details
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https://git.postgresql.org/pg/commitdiff/5a32af3f2c6106080da72e78a42c8fc3ab0584a1

Modified Files
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src/test/isolation/expected/search-path-inval.out | 97 -----------------------
src/test/isolation/isolation_schedule             |  1 -
src/test/isolation/specs/search-path-inval.spec   | 59 --------------
3 files changed, 157 deletions(-)