Stop new snyk pipeline schedule while being developed

[donoghuc]

This pipeline is running on a schedule but still needs work. It is polluting the notifications channel with failures. This commit removes the schedule while the pipeline is still under development. This can be reverted once it is in a working state and expected to pass consistently.

[github-actions]

🤖 GitHub comments

Just comment with:

• run docs-build : Re-trigger the docs validation. (use unformatted text in the comment!)
• /run exhaustive tests : Run the exhaustive tests Buildkite pipeline.

[mergify]

This pull request does not have a backport label. Could you fix it @donoghuc? 🙏
To fixup this pull request, you need to add the backport labels for the needed
branches, such as:

• backport-8./d is the label to automatically backport to the 8./d branch. /d is the digit.
• If no backport is necessary, please add the backport-skip label

[donoghuc]

The fix is actually closer than I thought #18499 Closing this.