Temporarily add build-essential to pure-rust-build job

This still installs `gcc` and `libc-dev` because `build-essential`
depends on them, but this als installs packages such as `g++` and
`make`, the absence of which seems to trigger failure before the
effects of installing the `minimal` toolchain do (if they do).

As in the previous change, this will of course need to be undone.

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 cmake # gcc is required as OS abstraction
+        run: apt-get update && apt-get install --no-install-recommends -y ca-certificates curl build-essential 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