debian: do Use ${env:...} syntax for installing with rename

This wasn't supported by older dh-exec but it is now, so let's use it to
be more consistent with other files

debian/authd-example-broker.install

@@ -1,6 +1,6 @@
 #!/usr/bin/dh-exec
 
-usr/bin/examplebroker-bin => ${AUTHD_DAEMONS_PATH}/authd-examplebroker
+usr/bin/examplebroker-bin => ${env:AUTHD_DAEMONS_PATH}/authd-examplebroker
 
 examplebroker/com.ubuntu.authd.ExampleBroker.conf /usr/share/dbus-1/system.d
 examplebroker/com.ubuntu.authd.ExampleBroker.service /usr/share/dbus-1/system-services

debian/authd.install

@@ -11,4 +11,4 @@ ${env:BUILT_PAM_LIBS_PATH}/pam_authd.so ${env:AUTHD_PAM_MODULES_PATH}
 ${env:BUILT_PAM_LIBS_PATH}/go-loader/pam_go_loader.so ${env:AUTHD_PAM_MODULES_PATH}
 
 # Install NSS library with right soname
-target/${DEB_HOST_RUST_TYPE}/release/libnss_authd.so => /usr/lib/${DEB_TARGET_GNU_TYPE}/libnss_authd.so.2
+target/${env:DEB_HOST_RUST_TYPE}/release/libnss_authd.so => /usr/lib/${env:DEB_TARGET_GNU_TYPE}/libnss_authd.so.2

debian/control

@@ -6,7 +6,7 @@ Build-Depends: debhelper-compat (= 13),
                dbus <!nocheck>,
                dh-apport,
                dh-cargo,
-               dh-exec,
+               dh-exec (>= 0.29),
                dh-golang,
                dctrl-tools,
                golang-go (>= 2:1.22~),