ci: Fix release workflow input booleans, remove snapshot (#5688)

* s/github.event.inputs/inputs/g

* Add run name and prevent non-dry-run releases on non-main branches

* Add logrun to lib.sh

scripts/lib.sh

@@ -131,11 +131,18 @@ maybedryrun() {
 		log "DRYRUN: $*"
 	else
 		shift
-		log $ "$@"
-		"$@"
+		logrun "$@"
 	fi
 }
 
+# logrun prints the given program and flags, and then executes it.
+#
+# Usage: logrun gh release create ...
+logrun() {
+	log $ "$*"
+	"$@"
+}
+
 # log prints a message to stderr.
 log() {
 	echo "$*" 1>&2