Temporarily add cmake to pure-rust-build job

This needs to be undone, since `max-pure` definitely should not
require `cmake`. The reason for this temporary change is to figure
out how robust the test is: currently, it fails on `max` as it
should, but reports the absence of `cmake` as the reason. For the
test to be robust, its failure should be for a deeper reason, and
preferably even implicate the `minimal` Rust profile.

Author: EliahKagan

.github/workflows/ci.yml

@@ -24,7 +24,7 @@ jobs:
     steps:
       - uses: actions/checkout@v4
       - name: Prerequisites
-        run: apt-get update && apt-get install --no-install-recommends -y ca-certificates curl gcc libc-dev # gcc is required as OS abstraction
+        run: apt-get update && apt-get install --no-install-recommends -y ca-certificates curl gcc libc-dev cmake # gcc is required as OS abstraction
       - name: install Rust via Rustup
         run: curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs | sh -s -- -y --profile minimal;
       - uses: Swatinem/rust-cache@v2