[release] Prefer vendoring local pip installation

caisar.opam

@@ -50,7 +50,7 @@ build: [
     jobs
     "--promote-install-files=false"
     "@install"
-    "@ensures-onnx"
+    "@ensures-onnx" {with-test}
     "@runtest" {with-test}
     "@doc" {with-doc}
   ]

caisar.opam.template

@@ -9,7 +9,7 @@ build: [
     jobs
     "--promote-install-files=false"
     "@install"
-    "@ensures-onnx"
+    "@ensures-onnx" {with-test}
     "@runtest" {with-test}
     "@doc" {with-doc}
   ]

tests/dune

-(rule
-  (alias ensures-onnx)
-  (deps (package caisar))
-  (action
-    (system "curl https://bootstrap.pypa.io/get-pip.py -o get-pip.py && python3 get-pip.py && python3 -m pip install onnx"))
-)
-
 (cram
  (alias local)
  (applies_to * \ nir_to_onnx acasxu_ci arithmetic comparison sequencing)
@@ -80,3 +73,10 @@
   ../lib/xgboost/example/california.csv
   ../lib/xgboost/example/california.json)
  (package caisar))
+
+(rule
+  (alias ensures-onnx)
+  (deps get-pip.py)
+  (action
+    (system "python3 get-pip.py && python3 -m pip install onnx"))
+)