Bumps Features/DFCI from 2.0.2 to 2.3.1

Introduces 6 new commits in [Features/DFCI](https://github.com/microsoft/mu_feature_dfci).

<details>
<summary>Commits</summary>
<ul>
<li><a href="https://github.com/microsoft/mu_feature_dfci/commit/3b324ef716d609367e32480c96bdbbaf28c1f581">3b324e</a> [Bug] Revert invalid change which breaks DFCI Refresh from network. (<a href="https://github.com/microsoft/mu_feature_dfci/pull/61">#61</a>)</li>
<li><a href="https://github.com/microsoft/mu_feature_dfci/commit/4bf67f28993390a8fbdbd1522ffb838c3ab8c236">4bf67f</a> Make DFCI Lock Var Runtime accessible (<a href="https://github.com/microsoft/mu_feature_dfci/pull/64">#64</a>)</li>
<li><a href="https://github.com/microsoft/mu_feature_dfci/commit/0fc28dd31eaa21ff68a373dd1da40e42954ba46a">0fc28d</a> Revert VarPolicy locking change (<a href="https://github.com/microsoft/mu_feature_dfci/pull/70">#70</a>)</li>
<li><a href="https://github.com/microsoft/mu_feature_dfci/commit/769a6091b42e44b69195dc72f30c38d4bd7782df">769a60</a> Fix memory leak (<a href="https://github.com/microsoft/mu_feature_dfci/pull/66">#66</a>)</li>
<li><a href="https://github.com/microsoft/mu_feature_dfci/commit/4cd4265bb0431ea341f2cdee6495b5c2c8a8e904">4cd426</a> Fix duplicate name error when adding second firewall rule (<a href="https://github.com/microsoft/mu_feature_dfci/pull/73">#73</a>)</li>
<li><a href="https://github.com/microsoft/mu_feature_dfci/commit/426e8d513de072734935d7d38b5dd9aac606e0ba">426e8d</a> Remove references to a function removed long ago (<a href="https://github.com/microsoft/mu_feature_dfci/pull/76">#76</a>)</li>
</ul>
</details>

Signed-off-by: Project Mu Bot <[email protected]>