fix: add open tab params to inline completion protocol (#645)

## Problem
This is to fix a typo in
https://github.com/aws/language-server-runtimes/pull/638/files.

## Solution

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## License

By submitting this pull request, I confirm that my contribution is made
under the terms of the Apache 2.0 license.

Author: leigaol

runtimes/protocol/inlineCompletionWithReferences.ts

@@ -18,7 +18,7 @@ interface DocumentChangeParams {
 }
 
 interface OpenTabParams {
-    openTabFilepaths?: string
+    openTabFilepaths?: string[]
 }
 
 export type InlineCompletionWithReferencesParams = InlineCompletionParams &