Use BuildKit cache mounts for Cargo Docker builds

Author: lovasoa

Dockerfile

@@ -1,3 +1,5 @@
+# syntax=docker/dockerfile:1
+
 FROM --platform=$BUILDPLATFORM rust:1.95-slim AS builder
 
 WORKDIR /usr/src/sqlpage
@@ -12,10 +14,16 @@ RUN cargo init .
 RUN /usr/local/bin/setup-cross-compilation.sh "$TARGETARCH" "$BUILDARCH"
 
 COPY Cargo.toml Cargo.lock ./
-RUN /usr/local/bin/build-dependencies.sh
+RUN --mount=type=cache,target=/usr/local/cargo/registry,sharing=locked \
+    --mount=type=cache,target=/usr/local/cargo/git,sharing=locked \
+    --mount=type=cache,target=/usr/src/sqlpage/target \
+    /usr/local/bin/build-dependencies.sh
 
 COPY . .
-RUN /usr/local/bin/build-project.sh
+RUN --mount=type=cache,target=/usr/local/cargo/registry,sharing=locked \
+    --mount=type=cache,target=/usr/local/cargo/git,sharing=locked \
+    --mount=type=cache,target=/usr/src/sqlpage/target \
+    /usr/local/bin/build-project.sh
 
 # Default minimal image (busybox-based)
 FROM busybox:glibc AS minimal