uv: Add PYTHONUSERBASE env to uv

Adding the PYTHONUSERBASE env variable to uv the same as python3.hcl
allowing better compatibility between existing python/pip and uv,
allowing the one to use both pip and uv inter-changablity.

Author: wsutina

uv.hcl

@@ -2,6 +2,9 @@ description = "An extremely fast Python package installer and resolver, written
 binaries = ["*"]
 homepage = "https://astral.sh/"
 strip = 1
+env = {
+  "PYTHONUSERBASE": "${HERMIT_ENV}/.hermit/python",
+}
 
 platform "darwin" {
   source = "https://github.com/astral-sh/uv/releases/download/${version}/uv-${xarch}-apple-darwin.tar.gz"