Update dnf5.conf.5 to reflect change in fastestmirror behavior

doc/dnf5.conf.5.rst

@@ -966,10 +966,10 @@ configuration.
 ``fastestmirror``
     :ref:`boolean <boolean-label>`
 
-    If enabled, a metric is used to find the fastest available mirror.
-    This overrides the order provided by the mirrorlist/metalink file itself.
-    This file is often dynamically generated by the server to provide the best download speeds and enabling
-    fastestmirror overrides this.
+    If enabled, TCP socket latency is used to find the closest available mirror.
+    A mirror is then selected at random with less than twice the lowest latency for load balancing purposes.
+    This overrides the order provided by the mirrorlist/metalink file itself,
+    and does not take into consideration mirrorlist parameters such as mirror bandwidth nor preferred mirrors for client IP addresses.
 
     Default: ``False``.