Remove redundant braces for CSS units with unary minus

It's redundant since we have `operator fun <T: CSSUnit> CSSSizeValue<T>.unaryMinus(): CSSSizeValue<T> `

examples/web-landing/src/jsMain/kotlin/com/sample/style/Stylesheet.kt

@@ -36,7 +36,7 @@ object AppStylesheet : StyleSheet() {
         lineHeight(24.px)
 
         position(Position.Relative)
-        top((-32).px)
+        top(-32.px)
         marginLeft(8.px)
         fontSize(15.px)
         backgroundColor(rgba(39, 40, 44, .05))
@@ -45,7 +45,7 @@ object AppStylesheet : StyleSheet() {
 
         media(mediaMaxWidth(640.px)) {
             self style {
-                top((-16).px)
+                top(-16.px)
             }
         }
     }

examples/web-landing/src/jsMain/kotlin/com/sample/style/WtText.kt

@@ -8,7 +8,7 @@ object WtTexts : StyleSheet(AppStylesheet) {
         color(Color("#27282c"))
         fontSize(60.px)
         fontSize(AppCSSVariables.wtHeroFontSize.value(60.px))
-        letterSpacing((-1.5).px)
+        letterSpacing(-1.5.px)
         fontWeight(900)
         lineHeight(64.px)
         lineHeight(AppCSSVariables.wtHeroLineHeight.value(64.px))
@@ -121,7 +121,7 @@ object WtTexts : StyleSheet(AppStylesheet) {
         color(Color("#27282c"))
         fontSize(31.px)
         fontSize(AppCSSVariables.wtH2FontSize.value(31.px))
-        letterSpacing((-.5).px)
+        letterSpacing(-.5.px)
         fontWeight(700)
         lineHeight(40.px)
         lineHeight(40.px)