Fetch rules_rs zlib packages from Ubuntu snapshots (#42288)

## What changed

Patch `rules_rs` to download its pinned `aarch64` and `x86_64` Linux zlib
packages from the dated Ubuntu snapshot. Keep the package versions and SHA-256
checksums unchanged.

GitOrigin-RevId: ec9d48827e08a87a7f93029bc22611b8fd41cc82

MODULE.bazel

@@ -152,6 +152,7 @@ single_version_override(
     patches = [
         "//patches:rules_rs_build_script_deps_annotation.patch",
         "//patches:rules_rs_windows_msvc_linker.patch",
+        "//patches:rules_rs_zlib_snapshot_urls.patch",
     ],
     version = "0.0.96",
 )

patches/BUILD.bazel

@@ -10,6 +10,7 @@ exports_files([
     "rules_cc_rusty_v8_custom_libcxx.patch",
     "rules_rs_build_script_deps_annotation.patch",
     "rules_rs_windows_msvc_linker.patch",
+    "rules_rs_zlib_snapshot_urls.patch",
     "rusty_v8_prebuilt_out_dir.patch",
     "ring_windows_msvc_include_dirs.patch",
     "v8_bazel_rules.patch",

patches/rules_rs_zlib_snapshot_urls.patch

@@ -0,0 +1,21 @@
+# What: fetch the pinned Linux zlib packages from dated Ubuntu snapshots.
+# Scope: download URLs only; package versions and checksums are unchanged.
+# Backport of https://github.com/hermeticbuild/rules_rs/commit/81336041f1c092b94ba0d35384c4dfc03ce45a07
+
+diff --git a/rs/private/rustc_repository.bzl b/rs/private/rustc_repository.bzl
+--- a/rs/private/rustc_repository.bzl
++++ b/rs/private/rustc_repository.bzl
+@@ -11,11 +11,11 @@ _LINUX_ZLIB = {
+     "aarch64": struct(
+         libdir = "usr/lib/aarch64-linux-gnu",
+         sha256 = "cbe3d39ec32d3cc27c021ae4af11e7c67bdf9d700d573207e0941d4038056278",
+-        url = "https://ports.ubuntu.com/ubuntu-ports/pool/main/z/zlib/zlib1g_1.3.dfsg-3.1ubuntu2.1_arm64.deb",
++        url = "https://snapshot.ubuntu.com/ubuntu/20260801T000000Z/pool/main/z/zlib/zlib1g_1.3.dfsg-3.1ubuntu2.1_arm64.deb",
+     ),
+     "x86_64": struct(
+         libdir = "usr/lib/x86_64-linux-gnu",
+         sha256 = "7074b6a2f6367a10d280c00a1cb02e74277709180bab4f2491a2f355ab2d6c20",
+-        url = "https://archive.ubuntu.com/ubuntu/pool/main/z/zlib/zlib1g_1.3.dfsg-3.1ubuntu2.1_amd64.deb",
++        url = "https://snapshot.ubuntu.com/ubuntu/20260801T000000Z/pool/main/z/zlib/zlib1g_1.3.dfsg-3.1ubuntu2.1_amd64.deb",
+     ),
+ }