chore(deps): update dependency ember-cli-showdown to v9

[renovate[bot]]

This PR contains the following updates:

Package	Change	Age	Adoption	Passing	Confidence
ember-cli-showdown	^6.0.1 -> ^9.0.1

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Release Notes

empress/ember-cli-showdown (ember-cli-showdown)

### [`v7.0.0`](https://togithub.com/empress/ember-cli-showdown/blob/HEAD/CHANGELOG.md#v700--2023-07-02) [Compare Source](https://togithub.com/empress/ember-cli-showdown/compare/v6.0.1...v7.0.0) \================== - update to v4.12 with ember-cli-update [#​128](https://togithub.com/empress/ember-cli-showdown/issues/128) from [@​mansona](https://togithub.com/mansona) - use ember-auto-import to import showdown [#​126](https://togithub.com/empress/ember-cli-showdown/issues/126) from [@​mansona](https://togithub.com/mansona) - breaking: drop support for node < 16 [#​127](https://togithub.com/empress/ember-cli-showdown/issues/127) from [@​mansona](https://togithub.com/mansona)

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Configuration

📅 Schedule: Branch creation - At any time (no schedule defined), Automerge - At any time (no schedule defined).

🚦 Automerge: Disabled by config. Please merge this manually once you are satisfied.

♻ Rebasing: Whenever PR becomes conflicted, or you tick the rebase/retry checkbox.

🔕 Ignore: Close this PR and you won't be reminded about this update again.

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• [ ] If you want to rebase/retry this PR, check this box

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[renovate[bot]]

⚠ Artifact update problem

Renovate failed to update an artifact related to this branch. You probably do not want to merge this PR as-is.

♻ Renovate will retry this branch, including artifacts, only when one of the following happens:

• any of the package files in this branch needs updating, or
• the branch becomes conflicted, or
• you click the rebase/retry checkbox if found above, or
• you rename this PR's title to start with "rebase!" to trigger it manually

The artifact failure details are included below:

File name: yarn.lock

Type Error: URL.canParse is not a function
    at parseSpec (/opt/containerbase/tools/corepack/0.26.0/18.14.2/node_modules/corepack/dist/lib/corepack.cjs:23359:21)
    at loadSpec (/opt/containerbase/tools/corepack/0.26.0/18.14.2/node_modules/corepack/dist/lib/corepack.cjs:23422:11)
    at async Engine.findProjectSpec (/opt/containerbase/tools/corepack/0.26.0/18.14.2/node_modules/corepack/dist/lib/corepack.cjs:23606:22)
    at async Engine.executePackageManagerRequest (/opt/containerbase/tools/corepack/0.26.0/18.14.2/node_modules/corepack/dist/lib/corepack.cjs:23660:20)
    at async BinaryCommand.validateAndExecute (/opt/containerbase/tools/corepack/0.26.0/18.14.2/node_modules/corepack/dist/lib/corepack.cjs:21164:22)
    at async _Cli.run (/opt/containerbase/tools/corepack/0.26.0/18.14.2/node_modules/corepack/dist/lib/corepack.cjs:22139:18)
    at async Object.runMain (/opt/containerbase/tools/corepack/0.26.0/18.14.2/node_modules/corepack/dist/lib/corepack.cjs:24371:12)