Fix the nix shell for RK provenance builds

We need bazel now, so the #rust shell isn't sufficient.

(For example:
https://github.com/project-oak/oak/actions/runs/10318293627/job/28564351573)

Change-Id: I48f1c308f079352cf29f7c37ea87abaeedc6a4af

buildconfigs/oak_restricted_kernel_simple_io_init_rd_wrapper_bin.sh

@@ -7,7 +7,7 @@ export PACKAGE_NAME=oak_restricted_kernel_simple_io_init_rd_wrapper_bin
 export BUILD_COMMAND=(
   nix
   develop
-  .#rust
+  .#ci
   --command
   just
   oak_restricted_kernel_wrapper_simple_io_channel