sh: Switch yay to paru

Removed outdated `syu` symlink which just hooks into topgrade.
Replaced it with simple function that tries for topgrade, paru, yay,
pacman, in that order. Can still be invoked with simple `syu` command,
but *only* through interactive terminal use.

Switched git pre-commit hook to default to paru instead of yay when
compiling installed package lists for dotfile commits.

sh/.config/sh/alias.d/syu.sh

@@ -0,0 +1,34 @@
+#!/usr/bin/env sh
+# Updates your system using topgrade if it exists,
+# falls back to paru or yay.
+# If only pacman exists, will use that but whine about it
+
+# Also makes yay call paru since that is the new hotness
+# (or at least I want to try it)
+
+type paru >/dev/null 2>&1 && {
+  alias yay=paru
+}
+
+syu() {
+  type topgrade >/dev/null 2>&1 && {
+    topgrade
+    return
+  }
+
+  type paru >/dev/null 2>&1 && {
+    paru
+    return
+  }
+
+  type yay >/dev/null 2>&1 && {
+    yay
+    return
+  }
+
+  type pacman >/dev/null 2>&1 && {
+    echo "Did not find paru, or yay installed. Updates will not be applied to aur packages."
+    sudo pacman -Syu
+    return
+  }
+}