update docker images

.woodpecker.yml

@@ -31,7 +31,7 @@ steps:
       - cargo fmt --check
 
   cargo_machete:
-    image: docker.io/rustlang/rust:nightly
+    image: *rust_image
     commands:
       - wget https://github.com/cargo-bins/cargo-binstall/releases/latest/download/cargo-binstall-x86_64-unknown-linux-musl.tgz
       - tar -xvf cargo-binstall-x86_64-unknown-linux-musl.tgz
@@ -40,7 +40,7 @@ steps:
       - cargo machete
 
   ignored_files:
-    image: docker.io/alpine:3
+    image: docker.io/alpine:latest
     commands:
       - apk add git
       - IGNORED=$(git ls-files --cached -i --exclude-standard)
@@ -82,7 +82,7 @@ steps:
     when: *slow_check_paths
 
   integration_test:
-    image: docker.io/debian-slim:latest
+    image: docker.io/alpine:latest
     commands:
       - ./test.sh