treewide: remove FHSEnv

To remove the FHSenv, we have to patch rules_python to use
/usr/bin/env to resolve the path to bash instead of hardcoding it.
Additionally, we now bring a Nix-compatible Bazel 8.

Change-Id: Id51e7748eea6dd77185f43a52fe45b5110ba4a2b
Reviewed-on: https://review.monogon.dev/c/monogon/+/4427
Tested-by: Jenkins CI
Reviewed-by: Jan Schär <jan@monogon.tech>
Reviewed-by: Lorenz Brun <lorenz@monogon.tech>
Reviewed-by: Leopold Schabel <leo@monogon.tech>
diff --git a/build/bazel/toolchain.MODULE.bazel b/build/bazel/toolchain.MODULE.bazel
index f0434f5..f691078 100644
--- a/build/bazel/toolchain.MODULE.bazel
+++ b/build/bazel/toolchain.MODULE.bazel
@@ -3,17 +3,17 @@
 http_archive(
     name = "toolchain-bundle-x86_64-unknown-linux-musl",
     build_file = "//build/toolchain/toolchain-bundle:toolchain-bundle.bzl",
-    integrity = "sha256-tpbvNL5S4t2WLkcj027sghf8tEzVJFL1e5leyx8JkCI=",
+    integrity = "sha256-7wceZhsWdZLXT2KW05NmmbUCYKA+DmudjPqTO3qX29I=",
     urls = [
-        "https://storage.googleapis.com/monogon-infra-public/toolchain/toolchain-bundle-x86_64-unknown-linux-musl-release-25.05.ffdcefdde9a4e540d1c875767da0e382e1ccf460.tar.zst",
+        "https://storage.googleapis.com/monogon-infra-public/toolchain/9iv889bzlsg1dglkmqdnabak5ffbp2km-toolchain/toolchain-bundle-x86_64-unknown-linux-musl.tar.zst",
     ],
 )
 
 http_archive(
     name = "toolchain-bundle-aarch64-unknown-linux-musl",
     build_file = "//build/toolchain/toolchain-bundle:toolchain-bundle.bzl",
-    integrity = "sha256-6caDQ8S+DGXHy2xSAhfRu5EXFLZ7NNqbtkY6o1i33F4=",
+    integrity = "sha256-7ckBNZ5186xDDsDlsUVMNIciY9nECfH70KoB/FUZKRc=",
     urls = [
-        "https://storage.googleapis.com/monogon-infra-public/toolchain/toolchain-bundle-aarch64-unknown-linux-musl-release-25.05.ffdcefdde9a4e540d1c875767da0e382e1ccf460.tar.zst",
+        "https://storage.googleapis.com/monogon-infra-public/toolchain/9iv889bzlsg1dglkmqdnabak5ffbp2km-toolchain/toolchain-bundle-aarch64-unknown-linux-musl.tar.zst",
     ],
 )