sh: Use relative alias for cat command

Fixes https://github.com/carapace-sh/carapace-bin/issues/2971
until the merge is in the new release version.

sh/.config/sh/alias.d/batcat.sh

@@ -13,8 +13,8 @@ alias rcat="$(which cat)"
 if command -v batcat >/dev/null 2>&1; then
     # For Ubuntu and Debian-based `bat` packages
     # the `bat` program is named `batcat` on these systems
-    alias cat="$(which batcat)"
+    alias cat="batcat"
 elif command -v bat >/dev/null 2>&1; then
     # For all other systems
-    alias cat="$(which bat)"
+    alias cat="bat"
 fi