ci: cache poetry
diff --git a/Earthfile b/Earthfile
index 230720e..757efed 100644
--- a/Earthfile
+++ b/Earthfile
@@ -2,7 +2,8 @@
 FROM python:3.10
 
 poetry:
-  RUN pip3 install poetry
+  RUN pip3 install poetry==1.4.2
+  SAVE IMAGE --cache-hint
 
 build.wheels:
   FROM +poetry