ci: fix kaniko builds and base images

.woodpecker.yml

@@ -6,7 +6,8 @@ steps:
   - name: build-and-push
     image: registry.nxtgauge.com/kaniko:2.1.1
     settings:
-      registry: registry.nxtgauge.com
+      registry:
+        from_secret: REGISTRY_HOSTPORT
       username:
         from_secret: REGISTRY_USERNAME
       password:

Dockerfile

@@ -1,4 +1,5 @@
 FROM registry.nxtgauge.com/rust:alpine AS builder
+RUN command -v cargo >/dev/null 2>&1 || apk add --no-cache cargo rust
 RUN apk add --no-cache musl-dev pkgconfig openssl-dev
 WORKDIR /app
 COPY Cargo.toml Cargo.lock* ./