Pull request links in changelog use "issue" instead of "pull" in the URLs

[WillGibson]

If the support paths suggested above still do not result in a resolution, please provide the following details.

Environment details

• Programming language: Python, though I'm not sure that has any bearing.
• OS: Ubuntu 24.04.1
• Language runtime version: 3.12.4, though I'm not sure that has any bearing.
• Package version: 16.12.0

Steps to reproduce

Use release please-action with the following configuration...

.github/workflows/create-release.yml

jobs:
  create-release:
    runs-on: ubuntu-latest
    steps:
      - uses: googleapis/release-please-action@v4
        with:
          token: ${{ secrets.GITHUB_TOKEN }}
          config-file: release-config.json
          manifest-file: release-manifest.json

release-config.json

{
  "$schema": "https://raw.githubusercontent.com/googleapis/release-please/main/schemas/config.json",
  "packages": {
    ".": {
        "release-type": "python",
        "include-v-in-tag": false,
        "draft": false,
        "pull-request-header": ":robot: Next release",
        "pull-request-footer": " "
    }
  }
}

CHANGELOG.md includes links like this...

[#764](https://github.com/uktrade/platform-tools/issues/764)

...when we would expect...

[#764](https://github.com/uktrade/platform-tools/pull/764)