Install Rust before make jerboa (native-bundle needs cargo)

ober

92162dcaa3956923c5bda9f1f3aa4cc667ce6a0c

diff --git a/.builds/ci.yml b/.builds/ci.yml
index f16f197..88a7561 100644
--- a/.builds/ci.yml
+++ b/.builds/ci.yml
@@ -19,6 +19,9 @@ sources:
 tasks:
 - build-jerboa: |
     cd jerboa
+    curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs | \
+      sh -s -- -y --profile minimal --default-toolchain 1.94.1
+    source "$HOME/.cargo/env"
     make jerboa CHEZ_CONFIGURE_EXTRA=--disable-x11
 - verify: |
     cd jerboa-gerbil