'xmlSubstituteEntitiesDefault' is deprecated, '__xmlLoadExtDtdDefaultValue' is deprecated

[ryandesign]

These warnings appear when compiling the latest code in the repository using libxml2 2.13.1:

pazpar2_config.c:1302:5: warning: 'xmlSubstituteEntitiesDefault' is deprecated [-Wdeprecated-declarations]
 1302 |     xmlSubstituteEntitiesDefault(1);
      |     ^
/opt/local/include/libxml2/libxml/parser.h:947:1: note: 'xmlSubstituteEntitiesDefault' has been explicitly marked deprecated here
  947 | XML_DEPRECATED XMLPUBFUN int
      | ^
/opt/local/include/libxml2/libxml/xmlexports.h:69:43: note: expanded from macro 'XML_DEPRECATED'
   69 |     #define XML_DEPRECATED __attribute__((deprecated))
      |                                           ^
pazpar2_config.c:1303:5: warning: '__xmlLoadExtDtdDefaultValue' is deprecated [-Wdeprecated-declarations]
 1303 |     xmlLoadExtDtdDefaultValue = 1;
      |     ^
/opt/local/include/libxml2/libxml/parser.h:896:37: note: expanded from macro 'xmlLoadExtDtdDefaultValue'
  896 |   #define xmlLoadExtDtdDefaultValue XML_GLOBAL_MACRO(xmlLoadExtDtdDefaultValue)
      |                                     ^
/opt/local/include/libxml2/libxml/xmlexports.h:124:36: note: expanded from macro 'XML_GLOBAL_MACRO'
  124 |   #define XML_GLOBAL_MACRO(name) (*__##name())
      |                                    ^
<scratch space>:2:1: note: expanded from here
    2 | __xmlLoadExtDtdDefaultValue
      | ^
/opt/local/include/libxml2/libxml/parser.h:885:1: note: '__xmlLoadExtDtdDefaultValue' has been explicitly marked deprecated here
  885 | XML_GLOBALS_PARSER
      | ^
/opt/local/include/libxml2/libxml/parser.h:881:3: note: expanded from macro 'XML_GLOBALS_PARSER'
  881 |   XML_GLOBALS_PARSER_CORE \
      |   ^
/opt/local/include/libxml2/libxml/parser.h:867:42: note: expanded from macro 'XML_GLOBALS_PARSER_CORE'
  867 |   XML_OP(xmlLoadExtDtdDefaultValue, int, XML_DEPRECATED) \
      |                                          ^
/opt/local/include/libxml2/libxml/xmlexports.h:69:43: note: expanded from macro 'XML_DEPRECATED'
   69 |     #define XML_DEPRECATED __attribute__((deprecated))
      |                                           ^