Fix --disable-exceptions builds

[roystgnr]

I broke our devel->master CI during the #4376 refactoring; this fixes the failing configure option for me.

[roystgnr]

The hell? This PR doesn't touch anything related to those Test Mac recipe failures:

../src/utils/xdr_cxx.C:565:12: error: cast from 'int (*)(XDR *, int *)' (aka 'int (*)(__rpc_xdr *, int *)') to 'xdrproc_t' (aka 'int (*)(__rpc_xdr *, void *, unsigned int)') converts to incompatible function type [-Werror,-Wcast-function-type-mismatch]
  565 |     return (xdrproc_t)(xdr_int);
      |            ^~~~~~~~~~~~~~~~~~~~

Plus who knows how many others (fatal error: too many errors emitted, stopping now [-ferror-limit=]).

Maybe this has something to do with the recent conda updates? I'll try just kicking it for the moment.

[moosebuild]

Job Test mac on 41463c3 : invalidated by @roystgnr

[moosebuild]

Job Coverage, step Generate coverage on 41463c3 wanted to post the following:

Coverage

	1a475b	#4378 41463c
	Total	Total	+/-	New
Rate	65.31%	65.30%	-0.01%	-
Hits	77592	77585	-7	0
Misses	41215	41222	+7	0

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