Reland "[infra] Update checked-in SDK to 2.17.0-266.1.beta"

This is a reland of commit bf2c56afbff51ed360ff99ae39582df0dd7fc457

Original change's description:
> [infra] Update checked-in SDK to 2.17.0-266.1.beta
>
> Bug: https://github.com/dart-lang/sdk/issues/48818
> Change-Id: Ic0658c7b60f12911f974f6580b3e378569b509c1
> Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/241516
> Auto-Submit: Alexander Thomas <athom@google.com>
> Reviewed-by: William Hesse <whesse@google.com>
> Commit-Queue: William Hesse <whesse@google.com>

Bug: https://github.com/dart-lang/sdk/issues/48818
Change-Id: I24bf97ec016594db94e3eba53fe10fc7c179fb00
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/241688
Bot-Commit: Rubber Stamper <rubber-stamper@appspot.gserviceaccount.com>
Commit-Queue: Alexander Aprelev <aam@google.com>
diff --git a/DEPS b/DEPS
index 0416bb7..a2c215f 100644
--- a/DEPS
+++ b/DEPS
@@ -39,7 +39,7 @@
 
   # 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:2.16.2",
+  "sdk_tag": "version:2.17.0-266.1.beta",
 
   # 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