chore(vscode): add SPDX license headers to new files

Signed-off-by: Adegbite Ayoade <tripleaceme@gmail.com>

Author: tripleaceme

vscode/extension/src/utilities/coalesceAsync.test.ts

@@ -1,3 +1,5 @@
+// SPDX-License-Identifier: Apache-2.0
+
 import { describe, expect, it } from 'vitest'
 import { coalesceAsync } from './coalesceAsync'
 

vscode/extension/src/utilities/coalesceAsync.ts

@@ -1,3 +1,5 @@
+// SPDX-License-Identifier: Apache-2.0
+
 /**
  * Serialize an async task so it never overlaps with itself, collapsing any
  * calls that arrive while it is running into a single rerun.

vscode/extension/src/utilities/common/configurationChange.test.ts

@@ -1,3 +1,5 @@
+// SPDX-License-Identifier: Apache-2.0
+
 import { describe, expect, it } from 'vitest'
 import { requiresLspRestart } from './configurationChange'
 

vscode/extension/src/utilities/common/configurationChange.ts

@@ -1,3 +1,5 @@
+// SPDX-License-Identifier: Apache-2.0
+
 /**
  * Configuration sections the language server reads, so a change to any of them
  * needs the server restarted to take effect.