Bump core from e9b17b3 to aa6e53f (Azure#320)

Bumps [core](https://github.com/microsoft/typespec) from `e9b17b3` to
`aa6e53f`.
<details>
<summary>Commits</summary>
<ul>
<li><a
href="https://github.com/microsoft/typespec/commit/aa6e53f4ab9a12dde617900cb1c4c68152527b61"><code>aa6e53f</code></a>
Add <code>getOpenAPI3</code> to OpenAPI3 emitter (<a
href="https://redirect.github.com/microsoft/typespec/issues/2950">#2950</a>)</li>
<li>See full diff in <a
href="https://github.com/microsoft/typespec/compare/e9b17b384d4dbe9ce0ee92c35f5c4332d275ff21...aa6e53f4ab9a12dde617900cb1c4c68152527b61">compare
view</a></li>
</ul>
</details>
<br />


Dependabot will resolve any conflicts with this PR as long as you don't
alter it yourself. You can also trigger a rebase manually by commenting
`@dependabot rebase`.

[//]: # (dependabot-automerge-start)
[//]: # (dependabot-automerge-end)

---

<details>
<summary>Dependabot commands and options</summary>
<br />

You can trigger Dependabot actions by commenting on this PR:
- `@dependabot rebase` will rebase this PR
- `@dependabot recreate` will recreate this PR, overwriting any edits
that have been made to it
- `@dependabot merge` will merge this PR after your CI passes on it
- `@dependabot squash and merge` will squash and merge this PR after
your CI passes on it
- `@dependabot cancel merge` will cancel a previously requested merge
and block automerging
- `@dependabot reopen` will reopen this PR if it is closed
- `@dependabot close` will close this PR and stop Dependabot recreating
it. You can achieve the same result by closing it manually
- `@dependabot show <dependency name> ignore conditions` will show all
of the ignore conditions of the specified dependency
- `@dependabot ignore this major version` will close this PR and stop
Dependabot creating any more for this major version (unless you reopen
the PR or upgrade to it yourself)
- `@dependabot ignore this minor version` will close this PR and stop
Dependabot creating any more for this minor version (unless you reopen
the PR or upgrade to it yourself)
- `@dependabot ignore this dependency` will close this PR and stop
Dependabot creating any more for this dependency (unless you reopen the
PR or upgrade to it yourself)


</details>

Signed-off-by: dependabot[bot] <[email protected]>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>