Remove Abseil dependency from CMake build

[acozzette]

We will reintroduce this soon, but we do not want it to take effect yet in the current 3.21 release.

[Mizux]

should NOT have been reverted same below

[yoavmil]

note that when I tried to install protobuf via vcpkg it gave an error message.
the install command:

PS ...\vcpkg> vcpkg upgrade protobuf:x64-windows --no-dry-run
The following packages will be rebuilt:
  * grpc[codegen,core]:x64-windows -> 1.49.0
  * protobuf[core]:x64-windows -> 3.21.6

the error message:

Error: Building package grpc:x64-windows failed with: BUILD_FAILED

and inside the log file:

CMake Error at CMakeLists.txt:2407 (target_link_libraries):
  Target "grpc" links to:

    absl::any_invocable

 vcpkg --version
Vcpkg package management program version 2022-03-09-1affd32f93b299d5a907816c328ca3ededb73a7e

[mkruskal-google]

protobuf doesn't depend on grpc, so there should be no reason we're causing an upgrade of it. It sounds like you have a more recent version of gRPC installed that depends on Abseil, but don't have Abseil installed