fix: try building from a base Alpine image and install cargo instead

Dockerfile

@@ -1,10 +1,14 @@
-ARG RUST_TAG=1.94.1-alpine3.23
-FROM rust:${RUST_TAG} AS builder
+ARG ALPINE_TAG=3.23
+FROM alpine:${ALPINE_TAG} AS builder
 
 ARG BUILD_BASE_VERSION=0.5-r3
 RUN --mount=type=cache,sharing=locked,target=/var/cache/apk \
     apk add --update build-base=${BUILD_BASE_VERSION}
 
+ARG CARGO_VERSION=1.91.1-r1
+RUN --mount=type=cache,sharing=locked,target=/var/cache/apk \
+    apk add --update cargo=${CARGO_VERSION}
+
 ARG CLANG21_DEV_VERSION=21.1.2-r2
 RUN --mount=type=cache,sharing=locked,target=/var/cache/apk \
     apk add --update clang21-dev=${CLANG21_DEV_VERSION}