Delete harvard-cardiff-university-old.csl (#6180)

Also deletes dependent prifysgol-caerdydd-harvard
closes #6179

Author: YoungZoe

dependent/prifysgol-caerdydd-harvard.csl

@@ -530,5 +530,7 @@
     "reach-reviews-in-human-space-exploration": "reach",
     "journal-of-oncological-science": "journal-of-oncological-sciences",
     "harvard-dublin-city-university": "harvard-cite-them-right",
-    "technische-universitat-dresden-medizin": "apa"
+    "technische-universitat-dresden-medizin": "apa",
+    "prifysgol-caerdydd-harvard": "cardiff-university-harvard",
+    "harvard-cardiff-university-old":"cardiff-university-harvard"
 }

harvard-cardiff-university-old.csl

@@ -4,7 +4,7 @@
     <title>The Journal of Hellenic Studies</title>
     <id>http://www.zotero.org/styles/the-journal-of-hellenic-studies</id>
     <link href="http://www.zotero.org/styles/the-journal-of-hellenic-studies" rel="self"/>
-    <link href="http://www.zotero.org/styles/harvard-cardiff-university-old" rel="template"/>
+    <link href="http://www.zotero.org/styles/cardiff-university-harvard" rel="template"/>
     <link href="http://www.hellenicsociety.org.uk/publications/" rel="documentation"/>
     <author>
       <name>Polly Low</name>