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_11_STABLE

Details
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https://git.postgresql.org/pg/commitdiff/4dc2cb74d00ed487ec785cdc66a5a5a0a9aa40b2

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