feat: add aurweb script wrappers

To call these externally, poetry run must be used. This
patch brings in some wrappers that call `poetry run`
within `{{ aurweb_dir }}`.

Signed-off-by: Kevin Morris <kevr@0cost.org>

roles/aurweb/templates/aurweb-git-auth.sh.j2

+#!/bin/bash
+cd "{{ aurweb_dir }}"
+exec poetry run aurweb-git-auth "$@"

roles/aurweb/templates/aurweb-git-serve.sh.j2

+#!/bin/bash
+cd "{{ aurweb_dir }}"
+exec poetry run aurweb-git-serve "$@"

roles/aurweb/templates/aurweb-git-update.sh.j2

+#!/bin/bash
+cd "{{ aurweb_dir }}"
+exec poetry run aurweb-git-update "$@"