ci: don't self-update rustup when using the rust-version script (#1209)

* ci: don't update rustup when using the rust-version script

* XXX: fake updates for triggering all

* Revert "XXX: fake updates for triggering all"

This reverts commit b343e61.

ci/rust-version.sh

@@ -45,7 +45,7 @@ export ci_docker_image="anzaxyz/ci:rust_${rust_stable}_${rust_nightly}"
     declare toolchain=$1
     if ! cargo +"$toolchain" -V > /dev/null; then
       echo "$0: Missing toolchain? Installing...: $toolchain" >&2
-      rustup install "$toolchain"
+      rustup install "$toolchain" --no-self-update
       cargo +"$toolchain" -V
     fi
   }