Update FIXME

Author: JohnTitor

.github/workflows/bors.yml

@@ -127,7 +127,8 @@ jobs:
           powerpc64le-unknown-linux-gnu,
           s390x-unknown-linux-gnu,
           riscv64gc-unknown-linux-gnu,
-          # FIXME: Figure out why this is disabled.
+          # FIXME: A recent nightly causes a linker failure:
+          # https://github.com/rust-lang/rust/issues/76679
           #wasm32-wasi,
           sparc64-unknown-linux-gnu,
           wasm32-unknown-emscripten,