chore: prepare for manylinux_2_35 and riscv64

This does not add or test either of those.

build.sh

@@ -19,6 +19,7 @@ case "${PLATFORM}" in
 	ppc64le) GOARCH="ppc64le";;
 	s390x) GOARCH="s390x";;
 	armv7l) GOARCH="arm/v7";;
+	riscv64) GOARCH="riscv64";;
 	*) echo "Unsupported platform: '${PLATFORM}'"; exit 1;;
 esac
 
@@ -47,6 +48,11 @@ elif [ "${POLICY}" == "manylinux_2_34" ]; then
 	DEVTOOLSET_ROOTPATH="/opt/rh/gcc-toolset-14/root"
 	PREPEND_PATH="/usr/local/bin:${DEVTOOLSET_ROOTPATH}/usr/bin:"
 	LD_LIBRARY_PATH_ARG="${DEVTOOLSET_ROOTPATH}/usr/lib64:${DEVTOOLSET_ROOTPATH}/usr/lib:${DEVTOOLSET_ROOTPATH}/usr/lib64/dyninst:${DEVTOOLSET_ROOTPATH}/usr/lib/dyninst"
+elif [ "${POLICY}" == "manylinux_2_35" ]; then
+	BASEIMAGE="ubuntu:22.04"
+	DEVTOOLSET_ROOTPATH=
+	PREPEND_PATH=
+	LD_LIBRARY_PATH_ARG=
 elif [ "${POLICY}" == "musllinux_1_2" ]; then
 	BASEIMAGE="alpine:3.21"
 	DEVTOOLSET_ROOTPATH=