Bump core from 3ed9b43 to c7dc05a (#1837)

Bumps [core](https://github.com/microsoft/typespec) from `3ed9b43` to
`c7dc05a`.
<details>
<summary>Commits</summary>
<ul>
<li><a
href="https://github.com/microsoft/typespec/commit/c7dc05aa56f10eab69974d7c4b2365ca7014ca32"><code>c7dc05a</code></a>
Implement TupleExpression (<a
href="https://redirect.github.com/microsoft/typespec/issues/5021">#5021</a>)</li>
<li><a
href="https://github.com/microsoft/typespec/commit/a2b314e8316b8df2f995d69621c66b5c31892bae"><code>a2b314e</code></a>
Add optional parameter support (<a
href="https://redirect.github.com/microsoft/typespec/issues/5041">#5041</a>)</li>
<li>See full diff in <a
href="https://github.com/microsoft/typespec/compare/3ed9b43ee1a17a77124a90cc785d32cb1372e9f5...c7dc05aa56f10eab69974d7c4b2365ca7014ca32">compare
view</a></li>
</ul>
</details>
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