roll: pigweed, pw_toolchain: pw_toolchain: Add linux_sysroot.bzl

This makes the code more robust against canonical repo changes, and is
necessary for supporting both bzlmod and WORKSPACE users.

Original-Bug: 258836641
Original-Reviewed-on: https://pigweed-review.googlesource.com/c/pigweed/pigweed/+/223578
Lint: Lint 🤖 <android-build-ayeaye@system.gserviceaccount.com>

https://pigweed.googlesource.com/pigweed/pigweed
pigweed, pw_toolchain Rolled-Commits: 7dc26abc274fa80..a98647d744dc24c
Roller-URL: https://ci.chromium.org/b/8742141210263919105
GitWatcher: ignore
CQ-Do-Not-Cancel-Tryjobs: true
Change-Id: I6d2d1db60be5a7a0d5bdfa08e408010a0536e0b5
Reviewed-on: https://pigweed-review.googlesource.com/c/pigweed/quickstart/bazel/+/223971
Bot-Commit: Pigweed Roller <pigweed-roller@pigweed-service-accounts.iam.gserviceaccount.com>
Lint: Lint 🤖 <android-build-ayeaye@system.gserviceaccount.com>
Commit-Queue: Pigweed Roller <pigweed-roller@pigweed-service-accounts.iam.gserviceaccount.com>
diff --git a/WORKSPACE b/WORKSPACE
index e291014..1d3a5bd 100644
--- a/WORKSPACE
+++ b/WORKSPACE
@@ -84,8 +84,8 @@
     name = "pigweed",
     # ROLL: Warning: this entry is automatically updated.
     # ROLL: Last updated 2024-07-17.
-    # ROLL: By https://cr-buildbucket.appspot.com/build/8742141602178117745.
-    commit = "7dc26abc274fa80d6c9f9de9e3a12e679795743d",
+    # ROLL: By https://cr-buildbucket.appspot.com/build/8742141210263919105.
+    commit = "a98647d744dc24cbbc7bac44b40dd4e0b255f7e5",
     remote = "https://pigweed.googlesource.com/pigweed/pigweed.git",
 )
 
@@ -93,8 +93,8 @@
     name = "pw_toolchain",
     # ROLL: Warning: this entry is automatically updated.
     # ROLL: Last updated 2024-07-17.
-    # ROLL: By https://cr-buildbucket.appspot.com/build/8742141602178117745.
-    commit = "7dc26abc274fa80d6c9f9de9e3a12e679795743d",
+    # ROLL: By https://cr-buildbucket.appspot.com/build/8742141210263919105.
+    commit = "a98647d744dc24cbbc7bac44b40dd4e0b255f7e5",
     remote = "https://pigweed.googlesource.com/pigweed/pigweed.git",
     strip_prefix = "pw_toolchain_bazel",
 )