roll: pigweed pw_protobuf: Support directly specifying options file locations

Replace the existing import-prefix arg to pwpb protoc plugin with an
option to directly specify the location of any .options files to load
from.

The import-prefix option was added to try and find options files whose
proto paths had been modified via the import_prefix bazel attr. This
worked fine as long as you were careful to place your options files in a
place where the existing search paths could find them.

We've found it's easy to break this arrangement if the real path of the
.options file isn't prefixed by the virtual import path of the proto.

This could be fixed by a further complicated dance of constructing
search paths that the plugin will then further mangle to check if the
options file exists.

This CL instead directly specifies the location of any options files for
the pwpb plugin, while leaving in place the existing search path logic
required for nanopb options files.

Original-Bug: https://pwbug.dev/253068333
Original-Reviewed-on: https://pigweed-review.googlesource.com/c/pigweed/pigweed/+/240833
Presubmit-Verified: CQ Bot Account <pigweed-scoped@luci-project-accounts.iam.gserviceaccount.com>
Original-Revision: 6efc99b3ee854dd54a0b1465d9014c54e01b21b9

Rolled-Repo: https://pigweed.googlesource.com/pigweed/pigweed
Rolled-Commits: 4321a46654fae2..6efc99b3ee854d
Roller-URL: https://ci.chromium.org/b/8734531451229149041
GitWatcher: ignore
CQ-Do-Not-Cancel-Tryjobs: true
Change-Id: I30dd33dd6d0f7d667b29568f4ce18f2d7d0ab858
Reviewed-on: https://pigweed-review.googlesource.com/c/pigweed/quickstart/bazel/+/241043
Commit-Queue: Pigweed Roller <pigweed-roller@pigweed-service-accounts.iam.gserviceaccount.com>
Bot-Commit: Pigweed Roller <pigweed-roller@pigweed-service-accounts.iam.gserviceaccount.com>
Lint: Lint 🤖 <android-build-ayeaye@system.gserviceaccount.com>
diff --git a/MODULE.bazel b/MODULE.bazel
index 424bf37..8c891bf 100644
--- a/MODULE.bazel
+++ b/MODULE.bazel
@@ -48,8 +48,8 @@
     module_name = "pigweed",
     # ROLL: Warning: this entry is automatically updated.
     # ROLL: Last updated 2024-10-09.
-    # ROLL: By https://cr-buildbucket.appspot.com/build/8734533988233259633.
-    commit = "4321a46654fae21df8e8fb971cd5c618b8b73d3f",
+    # ROLL: By https://cr-buildbucket.appspot.com/build/8734531451229149041.
+    commit = "6efc99b3ee854dd54a0b1465d9014c54e01b21b9",
     remote = "https://pigweed.googlesource.com/pigweed/pigweed",
 )
 
@@ -57,8 +57,8 @@
     module_name = "pw_toolchain",
     # ROLL: Warning: this entry is automatically updated.
     # ROLL: Last updated 2024-10-09.
-    # ROLL: By https://cr-buildbucket.appspot.com/build/8734533988233259633.
-    commit = "4321a46654fae21df8e8fb971cd5c618b8b73d3f",
+    # ROLL: By https://cr-buildbucket.appspot.com/build/8734531451229149041.
+    commit = "6efc99b3ee854dd54a0b1465d9014c54e01b21b9",
     remote = "https://pigweed.googlesource.com/pigweed/pigweed",
     strip_prefix = "pw_toolchain_bazel",
 )