ci: Work around sanitizer-related regression

```
     Running unittests src/lib.rs (target/debug/deps/futures_macro-cb16371840b70586)

/home/runner/work/futures-rs/futures-rs/target/debug/deps/futures_macro-cb16371840b70586: error while loading shared libraries: libstd-f157c25fb2dbfbe0.so: cannot open shared object file: No such file or directory
error: test failed, to rerun pass `-p futures-macro --lib`

Caused by:
  process didn't exit successfully: `/home/runner/work/futures-rs/futures-rs/target/debug/deps/futures_macro-cb16371840b70586 --skip panic_on_drop_fut` (exit status: 127)
```

Author: taiki-e

.github/workflows/ci.yml

@@ -275,7 +275,8 @@ jobs:
         run: rustup toolchain install nightly --component rust-src && rustup default nightly
       # https://github.com/google/sanitizers/issues/1716 / https://github.com/actions/runner-images/issues/9491
       - run: sudo sysctl vm.mmap_rnd_bits=28
-      - run: cargo -Z build-std test --workspace --all-features --target x86_64-unknown-linux-gnu --lib --tests -- --skip panic_on_drop_fut
+      # Exclude futures-macro to work around upstream bug since nightly-2024-10-06.
+      - run: cargo -Z build-std test --workspace --all-features --target x86_64-unknown-linux-gnu --lib --tests --exclude futures-macro -- --skip panic_on_drop_fut
         env:
           # TODO: Once `cfg(sanitize = "..")` is stable, replace
           # `cfg(futures_sanitizer)` with `cfg(sanitize = "..")` and remove