Use CBMC version 5.95.1

The upcoming CBMC version 6 release includes changes that may affect
existing proofs. This PR will make sure that
Device-Shadow-for-AWS-IoT-embedded-sdk PRs are not negatively impacted
by this release. After releasing CBMC version 6 we will issue a
follow-up PR that will return Device-Shadow-for-AWS-IoT-embedded-sdk to
using CBMC's latest release, and will include any changes to proofs that
may be necessary to support the new version.

.github/workflows/ci.yml

@@ -146,6 +146,8 @@ jobs:
     steps:
       - name: Set up CBMC runner
         uses: FreeRTOS/CI-CD-Github-Actions/set_up_cbmc_runner@main
+        with:
+          cbmc_version: "5.95.1"
       - name: Run CBMC
         uses: FreeRTOS/CI-CD-Github-Actions/run_cbmc@main
         with: