Change the default value of environment

Change the default value of the `environment` header to `any`.
Using `any` does not modify the built content therefore this PR
won't modify the existing SCE checks unless we add the `environment`
header explicitly.

docs/manual/developer/06_contributing_with_content.md

@@ -826,7 +826,7 @@ are unique to SCE:
    `rule.yml`, are added as a top-level OR-operator `<complex-check />` with
    the results of this `<complex-check />`.
  - `environment`: can be `normal`, `bootc`, `any`.
-   The default value that is used when this key is not set is `normal`.
+   The default value that is used when this key is not set is `any`.
    This key specifies the environment in which the SCE check can run in.
    This way you can restrict some SCE checks to run or not run in Image mode.
    If set to `bootc`, the SCE check code will be modified to not run outside of the bootable image build process.

ssg/build_sce.py

@@ -74,7 +74,7 @@ def _set_metadata_default_values(metadata):
         metadata['platform'] = metadata['platform'].split(',')
 
     if "environment" not in metadata:
-        metadata["environment"] = "normal"
+        metadata["environment"] = "any"
     environment_options = ["normal", "bootc", "any"]
     if metadata["environment"] not in environment_options:
         raise RuntimeError(