Report progress when uploading bottles

[p-linnane]

brew pr-upload prints nothing between formulae, so a large bottle upload can run for many minutes with no sign of how far along it is or whether it is stuck.

This adds formula-level progress to both upload backends, matching what the test jobs already print in Library/Homebrew/test_bot/formulae.rb:

==> Upload progress: 3 formula(e) uploaded, 0 remaining

It prints after each formula finishes and only when there are at least three formulae, so one and two formula uploads stay quiet. As in the test jobs, the count tracks formulae processed rather than bottles published, so a formula skipped under --warn-on-upload-failure still counts and its opoo line reports the skip.

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• I did not use AI/LLM to create this PR, or I disclosed the tool/model below and reviewed its output; I did not attribute commits to AI and will answer maintainer questions and review comments myself without AI/LLM.

Claude Code (Opus 5) drafted the implementation and tests; I reviewed the diff, verified the new ordering tests fail when progress is printed before the upload and pass when restored, and ran brew lgtm + targeted specs.

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[Copilot]

Pull request overview

This pull request adds formula-level progress output to brew pr-upload bottle uploads so long-running uploads provide visible feedback, matching the progress style used in the test-bot workflow.

Changes:

• Add per-formula progress reporting (only when uploading 3+ formulae) to the GitHub Releases and GitHub Packages upload backends.
• Add RSpec coverage for progress output presence/absence thresholds and for “skipped” (early-return) uploads still advancing progress.

Reviewed changes

Copilot reviewed 4 out of 4 changed files in this pull request and generated no comments.

File	Description
Library/Homebrew/github_releases.rb	Print progress after each formula upload when uploading 3+ formulae.
Library/Homebrew/github_packages.rb	Print progress after each formula upload when uploading 3+ formulae, while preserving the two-pass precheck/upload structure.
Library/Homebrew/test/github_releases_spec.rb	New specs asserting progress output ordering and suppression for <3 formulae.
Library/Homebrew/test/github_packages_spec.rb	New specs asserting progress output behavior and inclusion of skipped (early-return) cases.

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[MikeMcQuaid]

Thanks, good idea!