Remove loom and document possible improvements

.github/DOCS.md

@@ -23,3 +23,10 @@ As we don't currently have any meaningful feature gates.
 [source](https://github.com/jonhoo/rust-ci-conf/blob/main/.github/workflows/scheduled.yml#L1)
 
 As we don't run on nightly, we don't really need to check whether nightly breaks our builds. A potential argument for adding this could be that we are running nightly for the CI, and we could break the CI from nightly builds. I propose revisiting adding the `scheduled.yml` linked above if that's the case.
+
+### loom
+> Loom is a testing tool for concurrent Rust code. It runs a test many times, permuting the possible concurrent executions of that test under the C11 memory model. It uses state reduction techniques to avoid combinatorial explosion.
+
+[source](https://crates.io/crates/loom)
+
+Loom is great and it's backed by Tokio, but it would mean a bigger investment in making the threads we use be loom specific. Definitely something to iterate on, as we get onto Async Emacs.

.github/workflows/safety.yml

@@ -3,7 +3,6 @@
 # - miri - detects undefined behavior and memory leaks
 # - address santizer - detects memory errors
 # - leak sanitizer - detects memory leaks
-# - loom - Permutation testing for concurrent code https://crates.io/crates/loom
 # See check.yml for information about how the concurrency cancelation and workflow triggering works
 permissions:
   contents: read
@@ -73,18 +72,3 @@ jobs:
         run: cargo miri test
         env:
           MIRIFLAGS: "-Zmiri-strict-provenance"
-  loom:
-    runs-on: ubuntu-latest
-    steps:
-      - name: Install the required system libraries
-        run: sudo apt-get -y install libpango1.0-dev libgtk-3-dev
-      - uses: actions/checkout@v4
-        with:
-          submodules: true
-      - name: Install stable
-        uses: dtolnay/rust-toolchain@stable
-      - name: cargo test --test loom
-        run: cargo test --release --test loom
-        env:
-          LOOM_MAX_PREEMPTIONS: 2
-          RUSTFLAGS: "--cfg loom"