Release notes workflow update

[MarkWolters]

This PR updates the gha workflow for generating release notes in the following ways:

• Fixes a bug that caused the workflow to fail when path to release notes folder contains a space
• updates the workflow to check out a branch, generate the release notes, and generate a PR to main to merge the release notes. This replaces the functionality of simply creating a file on the branch where run and leaving the PR to be generated manually.

This PR also includes the release notes for release 4.0.0.-RC.9

[github-actions]

Before you submit for review:

• Does your PR follow guidelines from CONTRIBUTIONS.md?
• Did you summarize what this PR does clearly and concisely?
• Did you include performance data for changes which may be performance impacting?
• Did you include useful docs for any user-facing changes or features?
• Did you include useful javadocs for developer oriented changes, explaining new concepts or key changes?
• Did you rebase your branch onto the latest main for regression testing and PR submission?
• Did you trigger regression testing via Run Bench Main and review results?
• Did you adhere to the code formatting guidelines (TBD)
• Did you group your changes for easy review, providing meaningful descriptions for each commit?
• Did you ensure that all files contain the correct copyright header?
• Did you add documentation for this feature to the release notes directory?

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