pgsql: ci: Use newer LLVM version with gcc, to avoid compiler warnings

ci: Use newer LLVM version with gcc, to avoid compiler warnings

gcc emits a warning for LLVM 14 code outside of our control. To avoid that,
update to a newer LLVM version. Do so both in the CompilerWarnings and normal
tasks - the latter don't fail, but the warnings make it more likely that we'd
miss other warnings.

We might want to backpatch this eventually. The higher priority right now is
to unbreak CI though - which is only broken on master, due to 0c3930d0768
interacting badly with c8a6ec206a9 (mea culpa, I should have noticed this
before pushing, but I missed it due to another, independent CI failure).

Discussion: https://postgr.es/m/20240715193754.awdxgrzurxnwwu2t@awork3.anarazel.de

Branch
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master

Details
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https://git.postgresql.org/pg/commitdiff/4128453003dc755d94dfd661fb04d741f08e7fc8

Modified Files
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.cirrus.tasks.yml | 21 ++++++++++++---------
1 file changed, 12 insertions(+), 9 deletions(-)