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/toolchain/toolchain-bundle/toolchain-bundle.bzl b/build/toolchain/toolchain-bundle/toolchain-bundle.bzl
index 6ac17fb..c2de9d1 100644
--- a/build/toolchain/toolchain-bundle/toolchain-bundle.bzl
+++ b/build/toolchain/toolchain-bundle/toolchain-bundle.bzl
@@ -4,6 +4,32 @@
     "**/*",
 ]))
 
+filegroup(
+    name = "python3.12",
+    srcs = [
+        ":bin/python3.12",
+    ],
+    data = glob([
+        "lib/python3.12/**",
+    ]),
+)
+
+filegroup(
+    name = "python3.12_headers",
+    srcs = glob([
+        "include/python3.12/**",
+    ]),
+)
+
+filegroup(
+    name = "python3.12_libs",
+    srcs = glob([
+        "lib/python3.12/**",
+    ]) + [
+        ":lib/libpython3.12.a",
+    ],
+)
+
 # rules_perl expects all files as src entry, this does prevent us using
 # $(execpath) which is why we have another filegroup that uses this as
 # data dep.