Bump Ical.Net in /eFormAPI/Plugins/BackendConfiguration.Pn

Bumps [Ical.Net](https://github.com/ical-org/ical.net) from 4.2.0 to 4.3.1.
- [Release notes](https://github.com/ical-org/ical.net/releases)
- [Changelog](https://github.com/ical-org/ical.net/blob/main/history.md)
- [Commits](https://github.com/ical-org/ical.net/commits/v4.3.1)

---
updated-dependencies:
- dependency-name: Ical.Net
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot[bot]

eFormAPI/Plugins/BackendConfiguration.Pn/BackendConfiguration.Pn/BackendConfiguration.Pn.csproj

@@ -217,7 +217,7 @@
     <ItemGroup>
       <PackageReference Include="ChemicalsBase" Version="8.0.9" />
       <PackageReference Include="HtmlToOpenXml.dll" Version="3.2.0" />
-      <PackageReference Include="Ical.Net" Version="4.2.0" />
+      <PackageReference Include="Ical.Net" Version="4.3.1" />
       <PackageReference Include="Microting.eForm" Version="8.0.60" />
       <PackageReference Include="Microting.EformAngularFrontendBase" Version="8.0.60" />
       <PackageReference Include="Microting.eFormApi.BasePn" Version="8.0.60" />