build: DH-20954: Upgraded VS Code engine to ^1.105.0 (#264)

DH-20954: Upgraded VS Code engine to ^1.105.0

This is to bring in newer language model apis for building LM tools into
the extension. These tools are iterating pretty quickly, so targeting as
late as possible, but capping to 1.105.0 to accommodate latest Windsurf
version.

Also upgraded a few packages causing npm security errors.

## Testing
- Unit + regression tests should pass

Author: bmingles

.nvmrc

@@ -1 +1 @@
-v20.15.1
+v22.21.1

__mocks__/vscode.ts

@@ -146,20 +146,16 @@ export class Selection {
   active: Position;
 }
 
-export const ThemeColor = vi
-  .fn()
-  .mockName('ThemeColor')
-  .mockImplementation((id: string) => ({
-    id,
-  }));
-
-export const ThemeIcon = vi
-  .fn()
-  .mockName('ThemeIcon')
-  .mockImplementation((id: string, color?: typeof ThemeColor) => ({
-    id,
-    color,
-  }));
+export class ThemeColor {
+  constructor(public id: string) {}
+}
+
+export class ThemeIcon {
+  constructor(
+    public id: string,
+    public color?: ThemeColor
+  ) {}
+}
 
 export enum TreeItemCheckboxState {
   Unchecked = 0,