build: remove poetry.lock file

Since Moe doubles as a library, it doesn't make sense to keep the lock file in version control.

https://python-poetry.org/docs/libraries/#lock-file

Author: jtpavlock

.gitignore

@@ -80,3 +80,6 @@ dmypy.json
 
 # emacs configuration
 .dir-locals.el
+
+# poetry lock file
+poetry.lock