add oracle ipv6 single stack imds functionality

[a-dubs]

Proposed Commit Message

N/A

We rebasing 😎

Additional Context

This is to enable future functionality on the Oracle Cloud and will have no immediate ramifications or generally available use cases for the meantime.

Test Steps

These changes were manually tested on both jammy (22.04) and noble (24.04), on Oracle Platform Ubuntu images for testing ipv4 and dual stack, and then on custom built images for ipv6 single stack testing. For this manual validation, the following things were checked:

• No new warnings logged vs unmodified cloud-init package
• No boot speed slowdowns introduced vs unmodified cloud-int package

The new oracle single-stack ipv6 integration tests was run against an existing instance with the following command:

CLOUD_INIT_EXISTING_INSTANCE_ID="ocid1.instance............" \
CLOUD_INIT_PLATFORM="oci" \
CLOUD_INIT_RUN_UNSTABLE="true" \
CLOUD_INIT_KEEP_INSTANCE="true" \
tox -e integration-tests -- \
tests/integration_tests/datasources/test_oracle_ipv6.py

Merge type

• Squash merge using "Proposed Commit Message"
• Rebase and merge unique commits. Requires commit messages per-commit each referencing the pull request number (#<PR_NUM>)