Fix invalid directive bindings (#19330)

src/dialogs/generic/dialog-box.ts

@@ -74,7 +74,7 @@ class DialogBox extends LitElement {
                 <ha-textfield
                   dialogInitialFocus
                   value=${ifDefined(this._params.defaultValue)}
-                  .placeholder=${ifDefined(this._params.placeholder)}
+                  .placeholder=${this._params.placeholder}
                   .label=${this._params.inputLabel
                     ? this._params.inputLabel
                     : ""}

tsconfig.json

@@ -38,7 +38,6 @@
           "no-complex-attribute-binding": "warning",
           "no-nullable-attribute-binding": "warning",
           "no-incompatible-type-binding": "warning",
-          "no-invalid-directive-binding": "warning",
           // LitElement
           "no-incompatible-property-type": "warning",
           "no-property-visibility-mismatch": "warning",