Move typespec into sdk/core

[heaths]

Because typespec is just an implementation detail of core,
and to help simplify upcoming eng-sys changes that should make publishing easier,
move all the typespec crates under sdk/core.

[heaths]

@Hallir @danieljurek we talked about this a few days ago - that it should allow us to calculate the dependency order for all "core" crates. Do we want to move forward with this then? The sooner the better, because I have a few more core changes to make. It shouldn't affect anyway because we use workspace dependencies, and I did grep the repo (excluding target) for references to sdk/typespec. We'll also need to disable / archive the rust - typespec pipeline.

[Copilot]

Pull Request Overview

This PR moves the typespec-related crates from sdk/typespec to sdk/core to reflect that typespec is an implementation detail of core and to simplify upcoming engineering system changes for publishing.

The key changes include:

• Moving typespec crates from sdk/typespec/ to sdk/core/
• Updating workspace configuration and CI pipeline definitions
• Fixing documentation links to reflect the new locations

Reviewed Changes

Copilot reviewed 6 out of 78 changed files in this pull request and generated no comments.

Show a summary per file

File	Description
sdk/typespec/ci.yml	Removes the typespec-specific CI configuration file
sdk/core/typespec_macros/README.md	Updates source code link to new location under sdk/core
sdk/core/typespec_client_core/CHANGELOG.md	Updates README link to reflect new path location
sdk/core/ci.yml	Adds typespec artifacts to core CI configuration
Cargo.toml	Updates workspace member paths and dependency paths for typespec crates
.vscode/cspell.json	Updates spell checker path pattern to match new location