cad/cvc: Set USE_GCC=11

The build fails with GCC 12, which is soon to become GCC_DEFAULT.

PR:		266189
Reported by:	exp-run (antoine)
Approved by:	maintainer timeout (yuri, 2 weeks)

cad/cvc/Makefile

@@ -14,7 +14,8 @@ BUILD_DEPENDS=	pyinstaller:devel/py-pyinstaller@${PY_FLAVOR} \
 		bash:shells/bash
 
 USES=		autoreconf bison gettext-runtime gettext-tools gmake python readline shebangfix
-USE_GCC=	yes # clang fails, see https://github.com/d-m-bailey/cvc/issues/239
+USE_GCC=	11 # clang fails, see https://github.com/d-m-bailey/cvc/issues/239
+		   # GCC 12 fails, see https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=266189
 
 SHEBANG_FILES=	scripts/calibre_cvc scripts/clean_cvc_log scripts/expand_cells.py