Log activity when recording base image digests

[ralphbean]

The purpose is just to help users debug failures in the future. I have one such failure now where a later step complains that these base image digest lines are malformed. I'm just trying to get visibility on that.

[ralphbean]

FWIW, that other error I'm facing is:

[build-container : prepare-sboms] Merging contents of sbom-source.json and sbom-image.json into sbom-cyclonedx.json
[build-container : prepare-sboms] Merging contents of sbom-cachi2.json into sbom-cyclonedx.json
[build-container : prepare-sboms] Adding base images data to sbom-cyclonedx.json
[build-container : prepare-sboms] Traceback (most recent call last):
[build-container : prepare-sboms]   File "/scripts/base_images_sbom_script.py", line 354, in <module>
[build-container : prepare-sboms]     main()
[build-container : prepare-sboms]   File "/scripts/base_images_sbom_script.py", line 332, in main
[build-container : prepare-sboms]     base_images_digests = dict(item.split() for item in base_images_digests_raw)
[build-container : prepare-sboms]                           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[build-container : prepare-sboms] ValueError: dictionary update sequence element #1 has length 1; 2 is required

In konflux-ci/yq-container#88

Edit: Ah, it was #1791!