[abseil] Upgrade abseil to 20200923 patch 3, fix gcc11 build error

[x-projs]

Describe the pull request
Upgrade abseil to 20200923 patch 3, fix gcc11 build error

• What does your PR fix? Fixes #
  Upgrade abseil to 20200923 patch 3, fix gcc11 build error

• Which triplets are supported/not supported? Have you updated the CI baseline?
  abseil

• Does your PR follow the maintainer guide?

[PhoebeHui]

@xieyubo, thanks for the PR! Could you fix the baseline revision?

Error: While reading versions for port abseil from file: C:\a\1\s\versions\a-\abseil.json
       Version `2020-09-23#3` was not found in versions file.
       Run:
           vcpkg x-add-version abseil

       to add the new port version.
To attempt to resolve all errors at once, run:

    vcpkg x-add-version --all

##[error]PowerShell exited with code '1'.

[x-projs]

@PhoebeHui , thanks, fixed.

[ras0219-msft]

LGTM, thanks for the update!