fix: whitelist environment variables instead of passing all of them

Earlier applied fix d5f4fc9b86 introduced
errors with interaction, because (in docker container) HOME variable was
passed also to subprocesses. This fix limits variables to be passed to
the whitelisted ones

src/ahriman/core/util.py

@@ -129,7 +129,11 @@ def check_output(*args: str, exception: Exception | Callable[[int, list[str], st
     environment = environment or {}
     if user is not None:
         environment["HOME"] = getpwuid(user).pw_dir
-    full_environment = os.environ | environment
+    full_environment = {
+        key: value
+        for key, value in os.environ.items()
+        if key in ("PATH",)  # whitelisted variables only
+    } | environment
 
     with subprocess.Popen(args, cwd=cwd, stdin=subprocess.PIPE, stdout=subprocess.PIPE, stderr=subprocess.PIPE,
                           user=user, env=full_environment, text=True, encoding="utf8", bufsize=1) as process: