[roll recipes_version.txt] checkout: Add root_subdirectory property

Add a root_subdirectory property. If present, all commands will be run
from this subdirectory instead of the checkout root.

Original-Bug: 589
Original-Reviewed-on: https://pigweed-review.googlesource.com/c/infra/recipes/+/82944

https://pigweed.googlesource.com/infra/recipes
recipes_version.txt Rolled-Commits: cc7e73edbe7e744..a8ac556cc2f1cc7

GitOrigin-RevId: 55353f788ab722680e38b27a454accc3dbc6d302
Change-Id: Ic0223c2a6349f0bccfb29f59825661226e5bd89e
diff --git a/recipes_version.txt b/recipes_version.txt
index b9f41da..9293201 100644
--- a/recipes_version.txt
+++ b/recipes_version.txt
@@ -1 +1 @@
-cc7e73edbe7e7443f1f0678fa480a2eb757bec73
\ No newline at end of file
+a8ac556cc2f1cc74923f5e3873dc91b8688cb968
\ No newline at end of file