pip: update edk2-pytool-extensions requirement from ~=0.23.6 to ~=0.23.8 (#138)

Updates the requirements on
[edk2-pytool-extensions](https://github.com/tianocore/edk2-pytool-extensions)
to permit the latest version.

Signed-off-by: dependabot[bot] <support@github.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

pip-requirements.txt

@@ -13,7 +13,7 @@
 ##
 
 edk2-pytool-library~=0.15.3 # MU_CHANGE - update to 0.11.0 or later
-edk2-pytool-extensions~=0.23.6 # MU_CHANGE - update to 0.17.1 or later
+edk2-pytool-extensions~=0.23.8 # MU_CHANGE - update to 0.17.1 or later
 edk2-basetools==0.1.49 # MU_CHANGE - update to 0.1.13 or later
 antlr4-python3-runtime==4.13.0
 lcov-cobertura==2.0.2