Use TLS when Cloning Taxonomy Tree if CACert provided

[gmfrasca]

TLS-enabled git operations for Taxonomy

Description

If a CA Cert is provided in the form of a 'taxonomy-ca.crt' in the teacher-server ConfigMap, use TLS and said CA Cert to clone and fetch the taxonomy tree.

How Has This Been Tested?

To test, using a git repo that is accessed using a self-signed CA cert:

1. Import pipeline.yaml
2. For now, ensure teacher-server ConfigMap does NOT have a key named taxonomy-ca.crt
3. Run pipeline with default taxonomy repo pointer [Expected Result: Git Clone task should succeed]
4. Run with the taxonomy_repo parameter pointed to a git repo that can only be accessed using a self-signed CA cert. [Expected Result: Fails to clone]
5. Add the CA Certificate to teacher-server ConfigMap under the key taxonomy-ca.crt
6. Repeat Step 3. [Expected Result: Git Clone task should succeed]
7. Repeat Step 4. [Expected Result: Git Clone task should succeed]

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

[jgarciao]

As the recommended way to add CA bundles in RHOAI is to add them in the DSCInitialization (in .spec.trustedCABundle.customCABundle) and those bundles are already mounted in the pod running the task, I think the ilab pipeline should follow the same pattern and not use a different configmap to store the certificates

Update: discussed on slack: there are other pipeline steps that are also using the same mechanism. For this reason, I think it's fine the approach proposed by this PR for consistency.

[mprahl]

Optional:

Suggested change

	full_ca_path = os.path.abspath(f"{taxonomy_ca_cert_path}")
	full_ca_path = os.path.abspath(taxonomy_ca_cert_path)

[gmfrasca]

That variable is actually not a string - i believe its an InputParameterChannel or some other Pipelines construct, which abspath doesnt accept as a string-like type. Because of that, we need to expand it, as casting this specific type if it is None actually expands to the string "None" which would incorrectly pass this check

[gmfrasca]

/hold - container_component does not behave similarly to dsl.components when reading pod environments, need to update implementation

[gmfrasca]

/unhold

[HumairAK]

cc @tumido / @Shreyanand / @leseb / @MichaelClifford / et al