build: drop SwiftLint build-tool plugin from vendored CodeEdit packages

[datlechin]

Problem

Building on Xcode 27 / macOS 27 fails with Plug-in ended with uncaught signal: 5. The crash is the SwiftLint build-tool plugin bundled in the vendored CodeEdit packages:

swiftlint: .../SwiftLintBinary.artifactbundle/macos/swiftlint
SourceKittenFramework/library_wrapper.swift:58: Fatal error:
  Loading sourcekitdInProc.framework/Versions/A/sourcekitdInProc failed
** BUILD FAILED **

The prebuilt swiftlint binary can't load sourcekitd under the Xcode 27 toolchain. macOS 27 can't run the pinned Xcode 26.4.1, so there is no supported-toolchain workaround.

Change

Remove the SwiftLint build-tool plugin (and the SwiftLintPlugin dependency) from:

• LocalPackages/CodeEditSourceEditor/Package.swift
• LocalPackages/CodeEditTextView/Package.swift

That plugin lints CodeEdit's own vendored source, not TablePro code. TablePro lints itself with the root swiftlint + the CI lint gate, so nothing is lost. The app targets build unchanged; only the per-build lint of vendored third-party code is dropped.

Verification

xcodebuild ... build -skipPackagePluginValidation on Xcode 27 beta: BUILD SUCCEEDED.