[lint] Remove workaround for previous gaps in AST walking

lint/unused_import_analyzer.go

@@ -119,64 +119,6 @@ var UnusedImportAnalyzer = (func() *analysis.Analyzer {
 					}
 				},
 			)
-			// TODO: Remove the below section once https://github.com/onflow/cadence/issues/4470 is fixed.
-			// The Walk methods for composite, interface, and attachment declarations
-			// do not recurse into conformance lists, attachment base types, or
-			// entitlement access specifiers, so the inspector never visits the
-			// NominalType nodes there. Check those positions explicitly.
-
-			markNominalTypeUsed := func(t *ast.NominalType) {
-				name := t.Identifier.Identifier
-				if _, isImported := importedNames[name]; isImported {
-					usedImports[name] = struct{}{}
-				}
-			}
-
-			markEntitlementAccessUsed := func(access ast.Access) {
-				entAccess, ok := access.(ast.EntitlementAccess)
-				if !ok {
-					return
-				}
-				for _, e := range entAccess.EntitlementSet.Entitlements() {
-					markNominalTypeUsed(e)
-				}
-			}
-
-			inspector.Preorder(
-				[]ast.Element{
-					(*ast.CompositeDeclaration)(nil),
-					(*ast.InterfaceDeclaration)(nil),
-					(*ast.AttachmentDeclaration)(nil),
-					(*ast.FunctionDeclaration)(nil),
-					(*ast.FieldDeclaration)(nil),
-				},
-				func(element ast.Element) {
-					switch decl := element.(type) {
-					case *ast.CompositeDeclaration:
-						markEntitlementAccessUsed(decl.Access)
-						for _, c := range decl.Conformances {
-							markNominalTypeUsed(c)
-						}
-					case *ast.InterfaceDeclaration:
-						markEntitlementAccessUsed(decl.Access)
-						for _, c := range decl.Conformances {
-							markNominalTypeUsed(c)
-						}
-					case *ast.AttachmentDeclaration:
-						markEntitlementAccessUsed(decl.Access)
-						if decl.BaseType != nil {
-							markNominalTypeUsed(decl.BaseType)
-						}
-						for _, c := range decl.Conformances {
-							markNominalTypeUsed(c)
-						}
-					case *ast.FunctionDeclaration:
-						markEntitlementAccessUsed(decl.Access)
-					case *ast.FieldDeclaration:
-						markEntitlementAccessUsed(decl.Access)
-					}
-				},
-			)
 
 			// Collect unused imports.
 			// For implicit imports, we only report if ALL imports from that declaration are unused