Enable Azure dynamic agents for aarch64 Linux

[smlambert]

Similar to https://github.com/adoptium/aqa-tests/issues/5684, we can enable dynamic agents for aarch64 Linux. Before enabling, we should run through all 9 top-level test targets to check that there are limited or no failures due to running on this new type of agent.

To enable, we'd want to edit https://github.com/adoptium/aqa-tests/blob/master/buildenv/jenkins/openjdk_tests#L13-L16, by adding'DynamicAgents' : ['azure'] (see https://github.com/adoptium/aqa-tests/blob/master/buildenv/jenkins/openjdk_tests#L110).

We'd also need to say which image to use (which is why the naming of images is important. If the naming convention is standardized/predictable, the code to include new images will be kept very simple. This section https://github.com/adoptium/aqa-tests/blob/master/buildenv/jenkins/openjdk_tests#L575-L580 will need to be updated.

Later under a different issue, we will also want some logic that will cycle through the various types of images to ensure good coverage, instead of hard-coding to a single type for each platform/arch as we do know.