[apm][uptime][monitoring] Remove color="ghost" buttons (#169312)

## Summary

👋 Hey y'all - EUI will shortly be deprecating the `ghost` color in all
button components (see
https://eui.elastic.co/v89.0.0/#/navigation/button#ghost-vs-dark-mode).

In this PR, components using `color="ghost"` within an `EuiBottomBar`
already automatically inherit dark mode coloring and should be changed
to `color="text"` instead.

For the legacy uptime change that adds a theme wrapper, I'm unsure what
context it's being used in (does not appear to be a bottom bar) and
would appreciate help QAing it.

I'm opening this PR ahead of time for your team so you can test this
migration and ensure no UI regressions have occurred as a result.

### Checklist

- [ ] Tested in light and dark mode

---------

Co-authored-by: shahzad31 <shahzad31comp@gmail.com>

x-pack/plugins/apm/public/components/app/settings/bottom_bar_actions/index.tsx

@@ -42,7 +42,7 @@ export function BottomBarActions({
           }}
         >
           <EuiHealth color="warning" />
-          <EuiText color="ghost">
+          <EuiText>
             {i18n.translate('xpack.apm.bottomBarActions.unsavedChanges', {
               defaultMessage:
                 '{unsavedChangesCount, plural, =0{0 unsaved changes} one {1 unsaved change} other {# unsaved changes}} ',
@@ -55,7 +55,7 @@ export function BottomBarActions({
             <EuiFlexItem grow={false}>
               <EuiButtonEmpty
                 data-test-subj="apmBottomBarActionsDiscardChangesButton"
-                color="ghost"
+                color="text"
                 onClick={onDiscardChanges}
               >
                 {i18n.translate(

x-pack/plugins/monitoring/public/components/renderers/setup_mode.js

@@ -5,14 +5,7 @@
  * 2.0.
  */
 
-import {
-  EuiBottomBar,
-  EuiFlexGroup,
-  EuiFlexItem,
-  EuiIcon,
-  EuiSpacer,
-  EuiTextColor,
-} from '@elastic/eui';
+import { EuiBottomBar, EuiFlexGroup, EuiFlexItem, EuiIcon, EuiSpacer } from '@elastic/eui';
 import { FormattedMessage } from '@kbn/i18n-react';
 import React, { Fragment } from 'react';
 import { withKibana } from '@kbn/kibana-react-plugin/public';
@@ -144,15 +137,13 @@ export class WrappedSetupModeRenderer extends React.Component {
             <EuiFlexItem grow={false}>
               <EuiFlexGroup gutterSize="s">
                 <EuiFlexItem grow={false}>
-                  <EuiTextColor color="ghost">
-                    <FormattedMessage
-                      id="xpack.monitoring.setupMode.description"
-                      defaultMessage="You are in setup mode. The ({flagIcon}) icon indicates configuration options."
-                      values={{
-                        flagIcon: <EuiIcon type="flag" />,
-                      }}
-                    />
-                  </EuiTextColor>
+                  <FormattedMessage
+                    id="xpack.monitoring.setupMode.description"
+                    defaultMessage="You are in setup mode. The ({flagIcon}) icon indicates configuration options."
+                    values={{
+                      flagIcon: <EuiIcon type="flag" />,
+                    }}
+                  />
                 </EuiFlexItem>
               </EuiFlexGroup>
             </EuiFlexItem>

x-pack/plugins/uptime/public/legacy_uptime/components/settings/settings_actions.tsx

@@ -6,7 +6,7 @@
  */
 
 import React from 'react';
-import { EuiFlexGroup, EuiFlexItem, EuiButton, EuiButtonEmpty, EuiText } from '@elastic/eui';
+import { EuiFlexGroup, EuiFlexItem, EuiButton, EuiText } from '@elastic/eui';
 import { FormattedMessage } from '@kbn/i18n-react';
 import { euiStyled } from '@kbn/kibana-react-plugin/common';
 import { SettingsPageFieldErrors } from '../../pages/settings';
@@ -41,8 +41,8 @@ export const SettingsActions = ({
         </WarningText>
       </EuiFlexItem>
       <EuiFlexItem grow={false}>
-        <EuiButtonEmpty
-          color="ghost"
+        <EuiButton
+          color="text"
           size="s"
           iconType="cross"
           data-test-subj="discardSettingsButton"
@@ -55,7 +55,7 @@ export const SettingsActions = ({
             id="xpack.uptime.sourceConfiguration.discardSettingsButtonLabel"
             defaultMessage="Cancel"
           />
-        </EuiButtonEmpty>
+        </EuiButton>
       </EuiFlexItem>
       <EuiFlexItem grow={false}>
         <EuiButton