treewide: remove host_cc_toolchain, add static flags to linux platforms

With rules_rust now being able to build with our toolchain and sysroot,
we can finally get rid of the host_cc_toolchain.

Change-Id: Ic63bc34ff94d152a9c2d8a01a6036255da5e14cc
Reviewed-on: https://review.monogon.dev/c/monogon/+/4397
Tested-by: Jenkins CI
Reviewed-by: Jan Schär <jan@monogon.tech>
diff --git a/build/platforms/BUILD.bazel b/build/platforms/BUILD.bazel
index 028bb9a..c5c9838 100644
--- a/build/platforms/BUILD.bazel
+++ b/build/platforms/BUILD.bazel
@@ -5,6 +5,10 @@
         "@platforms//os:linux",
         "@platforms//cpu:x86_64",
     ],
+    flags = [
+        "--@toolchain_cc_mngn//buildmode:static",
+        "--@io_bazel_rules_go//go/config:static",
+    ],
     visibility = ["//visibility:public"],
 )
 
@@ -14,6 +18,10 @@
         "@platforms//os:linux",
         "@platforms//cpu:aarch64",
     ],
+    flags = [
+        "--@toolchain_cc_mngn//buildmode:static",
+        "--@io_bazel_rules_go//go/config:static",
+    ],
     visibility = ["//visibility:public"],
 )