test: disable nightly CI until #104 has been fixed

Author: bnjbvr

.github/workflows/main.yml

@@ -18,7 +18,7 @@ jobs:
       matrix:
         rust:
           - stable
-          - nightly
+          #- nightly # re-enable once #104 has been fixed
 
     steps:
       - uses: actions/checkout@v3