poolmanager: fix bad commit

Motivation:

Commit c0c11f4 removed support for the
'poolmanager.selection.unit.cachingenabeled' configuration property.

Unfortunately, the patch was incomplete as it neglected to remove the
Spring XML that injected this configuration property into the
PoolSelectionUnitV2 object, when initialising a \`poolmanager\` service.

This prevents a domain from starting if the domain is configured to run
the \`poolmanager\` service.

Modification:

Remove spring XML that (attempts to) set the \`cachingEnabeled\` property
in \`PoolSelectionUnitV2\`.

Result:

An unreleased regression is fixed.

Target: master
Requires-notes: no
Requires-book: no
Patch: https://rb.dcache.org/r/13976/
Acked-by: Tigran Mkrtchyan

modules/dcache/src/main/resources/diskCacheV111/poolManager/poolmanager.xml

@@ -34,7 +34,6 @@
   <bean id="psu" class="diskCacheV111.poolManager.PoolSelectionUnitV2">
     <description>Pool selection unit</description>
     <property name="pnfsHandler" ref="pnfs"/>
-    <property name="cachingEnabeled" value="${poolmanager.selection.unit.cachingenabeled}"/>
   </bean>
 
   <bean id="cm" class="diskCacheV111.poolManager.CostModuleV1">