Add guide for using Octopus Deploy's OIDC authentication during a GitHub Action Workflow

[zentron]

Why:

As per discussions, we are looking for Octopus Deploy's OIDC guide to be included alongside other 3rd party vendor guides.

What's being changed (if available, include any code snippets, screenshots, or gifs):

Additional page of content outlining how to use OIDC with Octopus Deploy to authenticate during a GitHub Action Workflow. The formatting is duplicated from the other existing guides.

Check off the following:

• A subject matter expert (SME) has reviewed the technical accuracy of the content in this PR. In most cases, the author can be the SME. Open source contributions may require a SME review from GitHub staff.
• The changes in this PR meet the docs fundamentals that are required for all content.
• All CI checks are passing.

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[github-actions]

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[github-actions]

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The table contains an overview of files in the content directory that have been changed in this pull request. It's provided to make it easy to review your changes on the staging site. Please note that changes to the data directory will not show up in this table.

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Content directory changes

You may find it useful to copy this table into the pull request summary. There you can edit it to share links to important articles or changes and to give a high-level overview of how the changes in your pull request support the overall goals of the pull request.

Source	Preview	Production	What Changed
New file: actions/security-for-github-actions/security-hardening-your-deployments/configuring-openid-connect-in-octopus-deploy.md	fpt ghec	fpt ghec
actions/security-for-github-actions/security-hardening-your-deployments/index.md	fpt ghec ghes@ 3.15 3.14 3.13 3.12 3.11 3.10	fpt ghec ghes@ 3.15 3.14 3.13 3.12 3.11 3.10

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fpt: Free, Pro, Team
ghec: GitHub Enterprise Cloud
ghes: GitHub Enterprise Server

[nguyenalex836]

@zentron Thanks so much for opening a PR! I'll get this triaged for review ✨

As per discussions

Do you by chance have a link where we can view these discussions? 💛

[zentron]

@nguyenalex836 apologies this was direct correspondence with Bekah Whittle from inside the GitHub team.

[github-actions]

Thanks for opening a pull request! We've triaged this issue for technical review by a subject matter expert 👀