Automatically pull updates for images in CI

.woodpecker/build.yml

@@ -6,6 +6,7 @@ platform: linux/amd64
 pipeline:
   unitTests:
     image: "docker.bics.ga/rei_ci/rust-sccache:latest-amd64"
+    pull: true
     commands:
       - DEBIAN_FRONTEND=noninteractive apt-get -qq update > /dev/null
       - DEBIAN_FRONTEND=noninteractive apt-get -yqq install pkg-config libssl-dev build-essential libsqlite3-dev > /dev/null
@@ -54,6 +55,7 @@ pipeline:
 
   deployManual:
     image: "docker.bics.ga/rei_ci/mdbook:latest-amd64"
+    pull: true
     when:
       branch:
         - develop