Log Message:
grpc: update to 1.66.1.

1.66.1

Core

    Enable EDS dualstack support by default (#37545)

1.66.0

This release contains refinements, improvements, and bug fixes, with highlights \ 
listed below.

Core

    [Python Otel] Manage call tracer life cycle use call arena. (v1.66.x \ 
backport). (#37479)
    [BoringSSL] Update third_party/boringssl-with-bazel. (#37223)
    [Dep] Upgrading Protobuf to v27.2. (#36753)
    [Gpr_To_Absl_Logging] Fixing bugs . (#36961)
    [chttp2] don't access endpoint in transport ops if it's already been \ 
destroyed. (#36921)

C++

    [OTel C++] Fix race when adding and removing callbacks (#37485). (#37508)
    [RlsLB] Fix Deadlock (#37459). (#37502)