Remove unnecessary semantic tokens capability check

Author: fwcd

Sources/SourceKitLSP/CapabilityRegistry.swift

@@ -142,11 +142,6 @@ public final class CapabilityRegistry {
     }
   }
 
-  /// Checks whether a registration for semantic tokens for the given language exists.
-  public func hasSemanticTokensRegistration(for language: Language) -> Bool {
-    registration(for: [language], in: semanticTokens) != nil
-  }
-
   private func documentSelector(for langauges: [Language]) -> DocumentSelector {
     return DocumentSelector(langauges.map { DocumentFilter(language: $0.rawValue) })
   }

Sources/SourceKitLSP/SourceKitServer.swift

@@ -855,49 +855,28 @@ extension SourceKitServer {
     languageService.documentColor(req)
   }
 
-  private func supportsSemanticTokens(in uri: DocumentURI) -> Bool {
-    guard let workspace = workspace,
-          let snapshot = workspace.documentManager.latestSnapshot(uri) else {
-      return false
-    }
-    let language = snapshot.document.language
-    return workspace.capabilityRegistry.hasSemanticTokensRegistration(for: language)
-  }
-
   func documentSemanticTokens(
     _ req: Request<DocumentSemanticTokensRequest>,
     workspace: Workspace,
     languageService: ToolchainLanguageServer
   ) {
-    if supportsSemanticTokens(in: req.params.textDocument.uri) {
-      languageService.documentSemanticTokens(req)
-    } else {
-      req.reply(DocumentSemanticTokensResponse(data: []))
-    }
+    languageService.documentSemanticTokens(req)
   }
 
   func documentSemanticTokensDelta(
     _ req: Request<DocumentSemanticTokensDeltaRequest>,
     workspace: Workspace,
     languageService: ToolchainLanguageServer
   ) {
-    if supportsSemanticTokens(in: req.params.textDocument.uri) {
-      languageService.documentSemanticTokensDelta(req)
-    } else {
-      req.reply(.tokens(.init(data: [])))
-    }
+    languageService.documentSemanticTokensDelta(req)
   }
 
   func documentSemanticTokensRange(
     _ req: Request<DocumentSemanticTokensRangeRequest>,
     workspace: Workspace,
     languageService: ToolchainLanguageServer
   ) {
-    if supportsSemanticTokens(in: req.params.textDocument.uri) {
-      languageService.documentSemanticTokensRange(req)
-    } else {
-      req.reply(DocumentSemanticTokensResponse(data: []))
-    }
+    languageService.documentSemanticTokensRange(req)
   }
 
   func colorPresentation(