add clang 16 and 17

Author: hanickadot

.github/workflows/tests.yml

@@ -40,7 +40,7 @@ jobs:
   clang:
     strategy:
       matrix:
-        clang: [7, 8, 9, 10, 11, 12, 13, 14, 15]
+        clang: [7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17]
         stdlib: ["libc++", "libstdc++"]
         standard: [17, 20]
       fail-fast: false