[roll] Roll fuchsia [roll] Roll gRPC, Abseil, and Protobuf

Roll third-party dependencies to get clean upstream revisions of
gRPC and Abseil:
- Roll third_party/grpc to v1.80.0.
- Roll third_party/abseil-cpp to LTS 2026-01.
- Roll third_party/protobuf to v35.0-rc1.

To support the newer gRPC and protobuf versions:
- Update third_party/grpc/BUILD.gn manually to support the promise-
  based HTTP2 transport and other Fuchsia-specific features (e.g.,
  bt-pandora-server), diverging from Chromium's templates.
- Update third_party/abseil-cpp/BUILD.gn for C++23 compatibility.
- Add Bazel MODULE overrides to align transitive rules (skylib,
  rules_python, rules_proto, etc.) and suppress older protobuf usage
  of newer rules.
- Flip the use_new_protobuf GN flag to true to activate compilation
  with the new protobuf sources.

Original-Original-Fixed: 524828429
Original-Original-Fixed: 524829635
Original-Original-Fixed: 524828279
Original-Original-Fixed: 468025056
NO_IFTTT=rules_rust version was not rolled, only single_version_override was updated

Original-Original-Reviewed-on: https://fuchsia-review.googlesource.com/c/fuchsia/+/1564015
SLSA-Policy-Verified: SLSA Policy Verification Service <devtools-gerritcodereview-exitgate@google.com>
Owners-Override: Adam Barth <abarth@google.com>
Original-Original-Revision: b92ddfcd63b43ff35855214807f3c8dc7e8a54af
GitOrigin-RevId: 3f11a5126617f084f1320d45ec54af9883e52682
Change-Id: Ie1a9645a233c4dcd179856290ecd651b146551a4
Reviewed-on: https://fuchsia-review.googlesource.com/c/integration/+/1689736
Cr-Commit-Position: refs/heads/main@{#195998}