Use CBMC version 5.95.1 (#289)

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

Test Steps
-----------
Tested in CI (no changes in behaviour at this point)

Checklist:
----------
<!--- Go over all the following points, and put an `x` in all the boxes
that apply. -->
<!--- If you're unsure about any of these, don't hesitate to ask. We're
here to help! -->
- [ ] I have tested my changes. No regression in existing tests.
- [ ] I have modified and/or added unit-tests to cover the code changes
in this Pull Request.

Related Issue
-----------
n/a

By submitting this pull request, I confirm that you can use, modify,
copy, and redistribute this contribution, under the terms of your
choice.

Co-authored-by: Tony Josi <tonyjosi@amazon.com>
Co-authored-by: Aniruddha Kanhere <60444055+AniruddhaKanhere@users.noreply.github.com>

.github/workflows/ci.yml

@@ -190,6 +190,8 @@ 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: