fix(FastAPI): Improve sqlite testing speed

This commit adds a new Arch dependency: `libeatmydata`, which
provides the `eatmydata` executable that stubs out fsync() operations.
We use `eatmydata` to run our sharness and pytests in Docker now.

With `autocommit=True`, required by SQLAlchemy to keep the
session up to date with external DB modifications, many fsync
calls are used in the SQLite backend; especially because we're wiping
and creating records in every DB-bound test.

**Before:**

- mysql: 1m42s (elapsed during pytest run)
- sqlite: 3m06s (elapsed during pytest run)

**After:**

- mysql: 1m40s (elapsed during pytest run)
- sqlite: 1m50s (elapsed during pytest run)

Shout out to @klausenbusk, who suggested this as a possible fix,
and it was. Thanks, Kristian!

Closes #120

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

docker/scripts/install-deps.sh

@@ -8,7 +8,7 @@ pacman -Syu --noconfirm --noprogressbar \
     --cachedir .pkg-cache git gpgme nginx redis openssh \
       mariadb mariadb-libs cgit uwsgi uwsgi-plugin-cgi \
       php php-fpm memcached php-memcached python-pip pyalpm \
-      python-srcinfo curl
+      python-srcinfo curl libeatmydata
 
 # https://python-poetry.org/docs/ Installation section.
 curl -sSL https://raw.githubusercontent.com/python-poetry/poetry/master/get-poetry.py | python -