fix(select): add missing filled type styles (#30763)

Issue number: resolves #

---------

This is based on
https://github.com/ionic-team/ionic-framework/pull/30755 PR to try to
clean up things.

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issue. -->

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## What is the current behavior?
- Select text color was not according design
- Fill solid type was missing the background color

## What is the new behavior?
- Added the expected color to the select text
- Added missing background color variable to the fill solid type

## Does this introduce a breaking change?

- [ ] Yes
- [X] No

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---------

Co-authored-by: ionitron <hi@ionicframework.com>

core/src/components/select/select.ionic.scss

@@ -38,6 +38,12 @@
 
 .select-text {
   min-width: globals.$ion-space-400;
+
+  color: globals.$ion-text-subtlest;
+}
+
+:host(.has-value) .select-text {
+  color: globals.$ion-text-default;
 }
 
 // Select Label
@@ -208,6 +214,12 @@
 
 .select-icon {
   transition: transform 0.15s globals.$ion-transition-curve-expressive;
+
+  color: globals.$ion-text-subtlest;
+}
+
+:host(.has-value) .select-icon {
+  color: globals.$ion-text-subtle;
 }
 
 /**
@@ -219,13 +231,15 @@
   @include globals.transform(rotate(180deg));
 }
 
-.select-icon {
-  color: globals.$ion-primitives-neutral-800;
-}
-
 // States
 // ----------------------------------------------------------------
 
+// Fill types
+// ----------------------------------------------------------------
+:host(.select-fill-solid) {
+  --background: #{globals.$ion-bg-input-bold-default};
+}
+
 // Disabled
 // ---------------------------------------------
 

core/src/components/select/test/custom/select.e2e.ts

@@ -57,6 +57,7 @@ configs({ modes: ['ios', 'md', 'ionic-md'], directions: ['ltr'] }).forEach(({ ti
         </div>
 
         <style>
+          ion-select::part(text),
           ion-select::part(container) {
             color: purple;
           }