00418: Don't generate sbom in make regen-all

The script and make target, modified in Python 3.13.0a4,
assumes the presence of expat and _decimal/libmpdec libraries, resulting in an
error and failed build when not found.
Reported upstream: python#115663

Makefile.pre.in

@@ -1625,10 +1625,11 @@ regen-unicodedata:
 regen-all: regen-cases regen-typeslots \
 	regen-token regen-ast regen-keyword regen-sre regen-frozen \
 	regen-pegen-metaparser regen-pegen regen-test-frozenmain \
-	regen-test-levenshtein regen-global-objects regen-sbom regen-jit
+	regen-test-levenshtein regen-global-objects regen-jit
 	@echo
 	@echo "Note: make regen-stdlib-module-names, make regen-limited-abi, "
-	@echo "make regen-configure and make regen-unicodedata should be run manually"
+	@echo "make regen-configure, make regen-unicodedata and make regen-sbom "
+	@echo "should be run manually"
 
 ############################################################################
 # Special rules for object files