Make `# gazelle:proto file` work without needing to set different `option go_package` in .proto files #1765

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@jeromep-stripe

The following contributors were found for this pull request:

✅ 0fbf13d Author: @jeromep-stripe <je****p@stripe.com>, <110950181+jeromep-stripe@users.noreply.github.com>
✅ 20e38de Author: @shahms <sh***s@google.com>
✅ 20e38de Co-Author: <fa***n@meumertzhe.im>
✅ 86505fb Author: @linzhp <z***n@uber.com>

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