rust: improve error handling of toml/jq install (#24)

Chains installation commands together to improve error handling.

The previous code would still catch errors, but the error messages would
be unclear "file not found" errors when running the final chmod commands.
Due to previous exit codes not being checked.

Signed-off-by: Alex Couture-Beil <alex@earthly.dev>

rust/Earthfile

@@ -60,8 +60,8 @@ get-tomljson:
     FROM alpine:3.18.3
     ARG USERARCH
     ARG version=2.1.0
-    RUN wget -O tomljson.tar.xz https://github.com/pelletier/go-toml/releases/download/v${version}/tomljson_${version}_linux_${USERARCH}.tar.xz; \
-        tar -xf tomljson.tar.xz; \
+    RUN wget -O tomljson.tar.xz https://github.com/pelletier/go-toml/releases/download/v${version}/tomljson_${version}_linux_${USERARCH}.tar.xz && \
+        tar -xf tomljson.tar.xz && \
         chmod +x tomljson
     SAVE ARTIFACT tomljson
 
@@ -70,7 +70,7 @@ get-jq:
     FROM alpine:3.18.3
     ARG USERARCH
     ARG version=1.7
-    RUN wget -O jq https://github.com/jqlang/jq/releases/download/jq-${version}/jq-linux-${USERARCH}; \
+    RUN wget -O jq https://github.com/jqlang/jq/releases/download/jq-${version}/jq-linux-${USERARCH} && \
         chmod +x jq
     SAVE ARTIFACT jq