build_sdk_board: make sure a python version is selected in the new SDK

BUG=b:230021530
TEST=`cros tryjob chromiumos-sdk-tryjob` passes

Change-Id: Ifcc190d15e72b65da712a7ba9e8715210b36291d
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/crosutils/+/3601570
Tested-by: Mike Frysinger <vapier@chromium.org>
Reviewed-by: Ryan Beltran <ryanbeltran@chromium.org>
Commit-Queue: Mike Frysinger <vapier@chromium.org>
diff --git a/build_sdk_board b/build_sdk_board
index 4af98d7..8d5297e 100755
--- a/build_sdk_board
+++ b/build_sdk_board
@@ -153,6 +153,10 @@
   virtual/target-sdk-nobdeps
 info_run sudo cp -a "${PKGDIR}" $BOARD_ROOT/packages
 
+# Make sure a version of Python is enabled since it might have raced above
+# when installing packages into the new root in parallel.
+info_run sudo env ROOT="${BOARD_ROOT}" eselect python update
+
 # Copy our chroot version into the newly packaged chroot.
 sudo cp -a "${CHROOT_VERSION_FILE}" "${BOARD_ROOT}${CHROOT_VERSION_FILE}"