pgsql: Fix instability in 026_overwrite_contrecord.pl test.

Fix instability in 026_overwrite_contrecord.pl test.

We've seen intermittent failures in this test on slower buildfarm
machines, which I think can be explained by assuming that autovacuum
emitted some additional WAL.  Disable autovacuum to stabilize it.

In passing, use stringwise not numeric comparison to compare
WAL file names.  Doesn't matter at present, but they are
hex strings not decimal ...

Discussion: https://postgr.es/m/1372189.1636499287@sss.pgh.pa.us

Branch
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REL_14_STABLE

Details
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https://git.postgresql.org/pg/commitdiff/3aa858c8932e91f74a2e7a7c3c237b345c4f0847

Modified Files
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src/test/recovery/t/026_overwrite_contrecord.pl | 9 +++++++--
1 file changed, 7 insertions(+), 2 deletions(-)