Bump Microsoft.Kiota.Abstractions from 1.7.6 to 1.7.8

Bumps [Microsoft.Kiota.Abstractions](https://github.com/microsoft/kiota-abstractions-dotnet) from 1.7.6 to 1.7.8.
- [Release notes](https://github.com/microsoft/kiota-abstractions-dotnet/releases)
- [Changelog](https://github.com/microsoft/kiota-abstractions-dotnet/blob/main/CHANGELOG.md)
- [Commits](microsoft/kiota-dotnet@v1.7.6...v1.7.8)

---
updated-dependencies:
- dependency-name: Microsoft.Kiota.Abstractions
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

Signed-off-by: dependabot[bot] <support@github.com>

src/Microsoft.Kiota.Serialization.Form.csproj

@@ -42,7 +42,7 @@
 
   <ItemGroup>
     <PackageReference Include="Microsoft.SourceLink.GitHub" Version="8.0.0" PrivateAssets="All" />
-    <PackageReference Include="Microsoft.Kiota.Abstractions" Version="1.7.6" />
+    <PackageReference Include="Microsoft.Kiota.Abstractions" Version="1.7.8" />
   </ItemGroup>
 
   <PropertyGroup Condition="'$(TF_BUILD)' == 'true'">