Add GNU/Hurd support

Author: sthibaul

.github/workflows/ci.yml

@@ -267,6 +267,7 @@ jobs:
           - target: x86_64-unknown-openbsd
           - target: armv7-unknown-linux-uclibceabihf
           - target: x86_64-unknown-haiku
+          - target: i686-unknown-hurd-gnu
     steps:
       - name: checkout
         uses: actions/checkout@v4