[Agent CI] Update signing pipeline to respect the new MinGit layout

[alexander-smolyakov]

Issue Description:

Recently our release pipeline failed with the following error on Verify Codesign Report pipeline step:

externals/git/mingw64/lib/python3.9/site-packages/libxml2mod.pyd(File,): error CI0001:  : The file is unsigned.

From the report, we can see that issue comes from the libxml2mod.pyd file that can be found by the following path externals/git/mingw64/lib/python3.9/site-packages

From Codesign Report

  FileName         : libxml2mod.pyd
  Ext              : PYD
  Path             : externals/git/mingw64/lib/python3.9/site-packages/libxml2mod.pyd
  OriginalFileName : 
  Version          : 
  Description      : 
  Product          : 
  Hash             : EA284B1DC6839A3D41DC1DB2DBFD1B237DAA77ECE4E20DBA0532D8271EFC13C3
  UserMode         : True
  Status           : Unsigned

The MinGW distribution comes from the Mingit distribution which we ship with the pipeline agent. Recently we have updated the Mingit version in this pull request:

• Bump git version to 2.36.1 #3839

The Mingit distribution layout was changed between versions 2.30.2 and 2.36.1 and now contains *.pyd files. In the Windows ecosystem, the *.pyd file is a dynamic link library (aka DLL) that contains a Python module or set of modules, to be called by other Python code.

Fix description:

Since *.pyd is a DLL file we need to sign it as well as other *.dll files which means that we have to update a list of patterns for the Sign Agent Assemblies (3rd Party Assemblies Signing) pipeline step to respect *.pyd files.

Changelog:

• signing.yml: Add pattern to sing the *.pyd files