update test matrix to start with ROCm 5.7.1

Signed-off-by: Karl W Schulz <karl.schulz@amd.com>

.github/workflows/mi100.yml

@@ -17,7 +17,7 @@ jobs:
   profile:
     strategy:
       matrix:
-        version: [5.5.1, 5.7.1]
+        version: [5.7.1]
       fail-fast: false
     runs-on: [mi100, rhel9]