Reorder method order to avoid int-conversion compilation issue

[fweimer-rh]

Without this change, GCC 14 will fail compilation with an error:

XADRAR5Parser.m: In function ‘+[XADRAR5Parser recognizeFileWithHandle:firstBytes:name:]’: XADRAR5Parser.m:79:5: warning: ‘XADRAR5Parser’ may not respond to ‘+signatureLocationInData:’
   79 |     off_t signatureLocation = [self signatureLocationInData:data];
      |     ^~~~~
XADRAR5Parser.m:79:5: warning: (messages without a matching method signature will be assumed to return ‘id’ and accept ‘...’ as arguments)
XADRAR5Parser.m:79:31: error: initialization of ‘off_t’ {aka ‘long int’} from ‘id’ makes integer from pointer without a cast
   79 |     off_t signatureLocation = [self signatureLocationInData:data];
      |                               ^

Related to:

• https://fedoraproject.org/wiki/Changes/PortingToModernC
• https://fedoraproject.org/wiki/Toolchain/PortingToModernC