fix(input_slider): Make sure last used handle is always above others (#4131)

tools/ion.rangeSlider-patches/0001-Add-skin-customized-for-Shiny.patch

@@ -3,7 +3,7 @@ new file mode 100644
 index 00000000..ba052f8b
 --- /dev/null
 +++ b/inst/www/shared/ionrangeslider/scss/shiny.scss
-@@ -0,0 +1,201 @@
+@@ -0,0 +1,206 @@
 +/* 'shiny' skin for Ion.RangeSlider, largely based on the 'big' skin, but with smaller dimensions, grayscale grid text, and without gradients
 +© Posit, PBC, 2023
 +© RStudio, Inc, 2014
@@ -149,6 +149,11 @@ index 00000000..ba052f8b
 +    border-radius: $handle_width;
 +    z-index: 2;
 +
++    &.type_last {
++      // Ensure last-used handle is on top if it overlaps with another handle
++      z-index: 3;
++    }
++
 +    &.state_hover,
 +    &:hover {
 +      background: $handle_color_hover;