pgsql: doc: Remove mention of Git protocol support

doc: Remove mention of Git protocol support

The project Git server hasn't supported cloning with the Git protocol
in a very long time, but the documentation never got the memo. Remove
the mention of using the Git protocol, and while there wrap a mention
of Git in <productname> tags.

Backpatch down to all supported versions.

Author: Daniel Gustafsson <daniel(at)yesql(dot)se>
Reported-by: Gurjeet Singh <gurjeet(at)singh(dot)im>
Reviewed-by: Nathan Bossart <nathandbossart(at)gmail(dot)com>
Reviewed-by: Jacob Champion <jacob(dot)champion(at)enterprisedb(dot)com>
Reviewed-by: Gurjeet Singh <gurjeet(at)singh(dot)im>
Reviewed-by: Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>
Discussion: https://postgr.es/m/CABwTF4WMiMb-KT2NRcib5W0C8TQF6URMb+HK9a_=rnZnY8Q42w@mail.gmail.com
Backpatch-through: 13

Branch
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REL_18_STABLE

Details
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https://git.postgresql.org/pg/commitdiff/172f217e825c63878b7b7c875ee04c7a90427303

Modified Files
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doc/src/sgml/sourcerepo.sgml | 12 +-----------
1 file changed, 1 insertion(+), 11 deletions(-)