ci: replace shellcheck image

.woodpecker/lint.yml

@@ -1,7 +1,7 @@
 ---
 steps:
   gitleaks:
-    image: zricethezav/gitleaks:v8.18.2
+    image: zricethezav/gitleaks:v8.18.2@sha256:eadfe256fa18d6a78a717abc9ed454c8e03865d1c46d627bca83977f4424901a
     commands:
       - gitleaks detect --no-git --verbose --source $CI_WORKSPACE
     when:
@@ -10,7 +10,7 @@ steps:
           - tag
 
   hadolint:
-    image: pipelinecomponents/hadolint:0.26.0
+    image: pipelinecomponents/hadolint:0.26.0@sha256:7122937006c7a9bcbb78ce764d3c2f0092f183b843ad128bc9fd6ea918e22d5b
     commands:
       - hadolint Dockerfile
     when:
@@ -19,7 +19,7 @@ steps:
           - tag
 
   shellcheck:
-    image: registry.mgrote.net/allzweckcontainer:latest
+    image: "koalaman/shellcheck-alpine:latest"
     commands:
       - |
         find . -type f -not -path './.git/*' -not -path './collections/*' -exec file {} \; | while IFS= read -r line; do
@@ -28,8 +28,4 @@ steps:
             shellcheck "$file_path"
           fi
         done
-    when:
-      event:
-        exclude:
-          - tag
 ...