Use image sha256 instead of tags

[DharmitD]

Description

Update images to use sha256 instead of tags, so that users can utilize them for scenarios such as disconnected cluster mirroring.

How Has This Been Tested?

Merge criteria:

• The commits are squashed in a cohesive manner and have meaningful messages.
• Testing instructions have been added in the PR body (for PRs involving changes that are not immediately obvious).
• The developer has manually tested the changes and verified that the changes work

[VaniHaripriya]

@DharmitD Please fix the pre-commit errors.

[DharmitD]

@DharmitD Please fix the pre-commit errors.

@VaniHaripriya Done, the CI runs passed successfully.

[VaniHaripriya]

/lgtm
Verified by executing make pipeline, which successfully generated the pipeline.yaml file.

$ make pipeline
python3 pipeline.py
/home/vmudadla/OpenshiftAI/ilab-on-ocp/training/components.py:339: SyntaxWarning: invalid escape sequence '\$'
  """
/home/vmudadla/OpenshiftAI/ilab-on-ocp/training/components.py:339: SyntaxWarning: invalid escape sequence '\$'
  """
Generating pipeline  [####################################]  100%                        
(venv) (base) [vmudadla@vmudadla-thinkpadp1gen3 ilab-on-ocp]$ git status
On branch image-shas
Your branch is up to date with 'dharmit-fork/image-shas'.

Changes not staged for commit:
  (use "git add <file>..." to update what will be committed)
  (use "git restore <file>..." to discard changes in working directory)
	modified:   importer-pipeline.yaml
	modified:   pipeline.yaml

Untracked files:
  (use "git add <file>..." to include in what will be committed)
	tests/dsp-ca.crt
	tests/ingress-operator.crt
	tests/server-cert.crt
	tests/server.crt

[HumairAK]

/lgtm