Update how-to-access-azureml-behind-firewall.md

[J-Silvestre]

The information provided is false.

Microsoft Container Registry is always needed, regardless of the scenario. This is because there are some base images that are always pulled from MCR in every environment build job. 2 Examples of these images given below:
mcr.microsoft.com/azumeml/runtime/cap/.................installed:westeurope-stable
mcr.microsoft.com/azumeml/runtime/exe/.................installed:westeurope-stable

[prmerger-automator]

@J-Silvestre : Thanks for your contribution! The author(s) have been notified to review your proposed change.

[learn-build-service-prod]

Learn Build status updates of commit 64c5317:

✅ Validation status: passed

File	Status	Preview URL	Details
articles/machine-learning/how-to-access-azureml-behind-firewall.md	✅Succeeded

For more details, please refer to the build report.

For any questions, please:

• Try searching the learn.microsoft.com contributor guides
• Post your question in the Learn support channel

[Court72]

@meerakurup

Can you review the proposed changes?

Important: When the changes are ready for publication, adding a #sign-off comment is the best way to signal that the PR is ready for the review team to merge.

#label:"aq-pr-triaged"
@MicrosoftDocs/public-repo-pr-review-team