Add next-release milestone via GitHub Actions workflow to automated PRs

[Copilot]

The milestone action used in mergify.yml does not exist in Mergify's current action schema, causing Mergify to report the config as invalid.

Changes proposed in this pull request

• .github/mergify.yml: Remove the invalid milestone rule (no such Mergify action exists)
• .github/workflows/milestone.yml: New pull_request_target workflow that assigns the next-release milestone to PRs from dependabot[bot], transifex-integration[bot], imgbot[bot], and Copilot (the correct GitHub login for the Copilot bot, which does not use the [bot] suffix) via actions/github-script; uses pull_request_target (no checkout) for elevated permissions, with minimal issues: write + pull-requests: write scopes; emits a warning rather than failing if the milestone doesn't exist yet

Related issue(s)

Copilot generated summary

Copilot summary

Removes a milestone action rule from .github/mergify.yml that referenced a non-existent Mergify action, restoring the config to a valid state. Replaces it with a dedicated GitHub Actions workflow (.github/workflows/milestone.yml) triggered on pull_request_target (opened/reopened) that locates the open next-release milestone by title and assigns it to any PR authored by the four automated bots: dependabot[bot], transifex-integration[bot], imgbot[bot], and Copilot. Note that the Copilot bot's GitHub login is Copilot (capital C, no [bot] suffix), unlike the other bots. The pull_request_target trigger is safe here because no code is checked out.

To-Do

• Update documentation to reflect this changes
• Update changelog to reflect this changes

Contributing

By submitting this pull request, I confirm the following:

• I have read and understood the contributing guidelines and the code of conduct.
• I have have added my name, username or email to the contributors list or don't want to.
• The code or resource is compatible with the GNU General Public License v3.0.

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[BornToBeRoot]

@copilot Can you also add copilot to the list.

[Copilot]

@copilot Can you also add copilot to the list.

Done — copilot[bot] has been added to the bot list in commit 7a356df.

[BornToBeRoot]

@copilot analyze the last PRs and check if Copilot is a bot in this case.Verify that the name is correct.

[Copilot]

@copilot analyze the last PRs and check if Copilot is a bot in this case.Verify that the name is correct.

Checked the last several PRs — Copilot's actual GitHub login is Copilot (capital C, no [bot] suffix), unlike dependabot[bot], transifex-integration[bot], and imgbot[bot]. Fixed in commit c33b3e6.