pgsql: Doc: update description of random() function.

Doc: update description of random() function.

Commit 3804539e4 neglected to update the documentation's claim that
random() uses a "linear congruential algorithm".  In hopes of avoiding
the same mistake if someone replaces our PRNG again, just say it's a
deterministic pseudo-random number generator and leave it at that.
Anybody who really wants to know can look in the source code.

COMPATIBILITY NOTE FOR RELEASE NOTES: 3804539e4's commit message
really should have mentioned that the random() sequence after
setseed(), while still repeatable, will differ from what you got
in pre-v15 releases.

Noted by Dagfinn Ilmari Mannsåker; wording suggestion by Dean Rasheed.

Discussion: https://postgr.es/m/875ynfpiru.fsf@wibble.ilmari.org

Branch
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master

Details
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https://git.postgresql.org/pg/commitdiff/d4f109e4a2c028bcd889cc44d84b10fff7d9186b

Modified Files
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doc/src/sgml/func.sgml | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)