Make documentation builds reproducible
Currently, the documentation builds are not fully reproducible (in the
sense of https://reproducible-builds.org/). A fix is available
upstream (https://github.com/docbook/xslt10-stylesheets/issues/54) but
not released. This commit patches the upstream fix into our
customization layer.
This patch addresses both the HTML and the FO output. The man output
is already reproducible.
Discussion: https://www.postgresql.org/message-id/flat/
9077b779-a9f8-09c8-6e85-
da1ebfba15af@eisentraut.org