gnu: PostgreSQL: Promote version 14 to the default.

* gnu/packages/databases.scm (postgresql): Alias to POSTGRESQL-14.
* gnu/packages/qt.scm (qtbase-5)[inputs]: Stay on POSTGRESQL-13.

gnu/packages/databases.scm

@@ -1315,7 +1315,7 @@ pictures, sounds, or video.")
        (append opensp docbook-sgml-4.2)
        (delete "docbook-xml")))))
 
-(define-public postgresql postgresql-13)
+(define-public postgresql postgresql-14)
 
 (define-public timescaledb
   (package

gnu/packages/qt.scm

@@ -354,7 +354,8 @@ system, and the core design of Django is reused in Grantlee.")
        ("nss" ,nss)
        ("openssl" ,openssl)
        ("pcre2" ,pcre2)
-       ("postgresql" ,postgresql)
+       ;; TODO: Switch to 'postgres' in the next rebuild cycle.
+       ("postgresql" ,postgresql-13)
        ("pulseaudio" ,pulseaudio)
        ("sqlite" ,sqlite)
        ("unixodbc" ,unixodbc)