DLPX-93264 24.04 LTS upgrade: kernel builds fail due to rustc conflict

PR URL: https://www.github.com/delphix/delphix-rust/pull/21

Author: palash-gandhi

RUSTC_VERSION

@@ -0,0 +1 @@
+1.80.0

debian/rules

@@ -16,12 +16,13 @@
 #
 
 DEB_HOST_GNU_CPU ?= $(shell dpkg-architecture -qDEB_HOST_GNU_CPU)
+RUSTC_VERSION := $(shell tr -d '\n' < RUSTC_VERSION)
 
 %:
 	dh $@
 
 override_dh_install:
-	./scripts/fetch-and-run-installer.sh "1.80.0" "/usr" "debian/tmp" $(DEB_HOST_GNU_CPU)
+	./scripts/fetch-and-run-installer.sh ${RUSTC_VERSION} "/usr" "debian/tmp" $(DEB_HOST_GNU_CPU)
 
 	dh_install --autodest "debian/tmp/*"