pip: bump edk2-pytool-extensions from 0.27.5 to 0.27.6 (#272)

Bumps
[edk2-pytool-extensions](https://github.com/tianocore/edk2-pytool-extensions)
from 0.27.5 to 0.27.6.

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==0.21.7
-edk2-pytool-extensions==0.27.5
+edk2-pytool-extensions==0.27.6
 antlr4-python3-runtime==4.13.1
 regex
 pygount==1.8.0