Update v3 Python Worker Version to 1.2.6 (#7696)

Python Worker Release note [1.2.6](https://github.com/Azure/azure-functions-python-worker/releases/tag/1.2.6)

Author: vrdmr

build/python.props

@@ -1,5 +1,5 @@
 <Project>
   <ItemGroup>
-    <PackageReference Include="Microsoft.Azure.Functions.PythonWorker" Version="3.1.2.5" />
+    <PackageReference Include="Microsoft.Azure.Functions.PythonWorker" Version="3.1.2.6" />
   </ItemGroup>
 </Project>

release_notes.md

@@ -2,6 +2,7 @@
 <!-- Please add your release notes in the following format:
 - My change description (#PR)
 -->
+- Update Python Worker Version to [1.2.6](https://github.com/Azure/azure-functions-python-worker/releases/tag/1.2.6)
 - Updated PowerShell Worker (PS7) to [3.0.1045](https://github.com/Azure/azure-functions-powershell-worker/releases/tag/v3.0.1045)
 
 **Release sprint:** Sprint 107

test/WebJobs.Script.Tests/WebJobs.Script.Tests.csproj

@@ -52,7 +52,7 @@
     <PackageReference Include="appinsights.testlogger" Version="1.0.0" />
     <PackageReference Include="FluentAssertions" Version="5.9.0" />
     <PackageReference Include="Microsoft.AspNetCore.TestHost" Version="3.1.0" />
-    <PackageReference Include="Microsoft.Azure.Functions.PythonWorker" Version="3.1.2.5" />
+    <PackageReference Include="Microsoft.Azure.Functions.PythonWorker" Version="3.1.2.6" />
     <PackageReference Include="Microsoft.NET.Test.Sdk" Version="16.9.4" />
     <PackageReference Include="Moq" Version="4.9.0" />
     <PackageReference Include="StyleCop.Analyzers" Version="1.1.0-beta004" />