[infra] Update checked-in SDKs to 2.10.0-0.0.dev

Change-Id: I9dc310aedbb91f9adfb6bfd1dd38b6045a8c1722
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/155601
Reviewed-by: Johnni Winther <johnniwinther@google.com>

Author: whesse

DEPS

@@ -39,7 +39,7 @@ vars = {
 
   # Checked-in SDK version. The checked-in SDK is a Dart SDK distribution in a
   # cipd package used to run Dart scripts in the build and test infrastructure.
-  "sdk_tag": "version:2.10.0-0.2-preview",
+  "sdk_tag": "version:2.10.0-0.0.dev",
 
   # co19 is a cipd package. Use update.sh in tests/co19[_2] to update these
   # hashes. It requires access to the dart-build-access group, which EngProd