pgsql: doc: Fix XML_CATALOG_FILES env var for Apple M1 machines

doc: Fix XML_CATALOG_FILES env var for Apple M1 machines

Homebrew changed the prefix for Apple M1 based machines, so our
advice for XML_CATALOG_FILES needs to mention both. More info
on the Homebrew change can be found at:

https://github.com/Homebrew/brew/issues/9177

Author: Julien Rouhaud <julien.rouhaud@free.fr>
Discussion: /messages/by-id/20230327082441.h7pa2vqiobbyo7rd@jrouhaud

Branch
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master

Details
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https://git.postgresql.org/pg/commitdiff/4c8d654084700f801f48827bb3531a6779b8b90e

Modified Files
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doc/src/sgml/docguide.sgml | 6 +++++-
1 file changed, 5 insertions(+), 1 deletion(-)