fix: remove duplicate running indicator from queue header (#9032)

## Summary
Remove the extra running-workflow indicator from the expanded Queue
Progress Overlay header to avoid duplicate running-count signals.

## Changes
- Remove `showConcurrentIndicator` and `concurrentWorkflowCount` props
from `QueueOverlayHeader`.
- Stop passing those props through `QueueOverlayExpanded` and
`QueueProgressOverlay`.
- Simplify `QueueOverlayHeader` tests to reflect the updated header
behavior.

## Why
The expanded header was showing redundant running status information
alongside existing running/queued summaries.

Prevent this:
<img width="240" height="92" alt="image"
src="https://github.com/user-attachments/assets/f4b1775c-b347-46f7-8668-3a1054365ada"
/>

Design:
https://www.figma.com/design/LVilZgHGk5RwWOkVN6yCEK/Queue-Progress-Modal?node-id=4024-28147&m=dev

┆Issue is synchronized with this [Notion
page](https://www.notion.so/PR-9032-fix-remove-duplicate-running-indicator-from-queue-header-30d6d73d365081d19041de2f1b0c8886)
by [Unito](https://www.unito.io)

---------

Co-authored-by: Johnpaul Chiwetelu <49923152+Myestery@users.noreply.github.com>
Co-authored-by: GitHub Action <action@github.com>

src/components/queue/QueueProgressOverlay.vue

@@ -17,8 +17,6 @@
         v-model:selected-sort-mode="selectedSortMode"
         class="flex-1 min-h-0"
         :header-title="headerTitle"
-        :show-concurrent-indicator="showConcurrentIndicator"
-        :concurrent-workflow-count="concurrentWorkflowCount"
         :queued-count="queuedCount"
         :displayed-job-groups="displayedJobGroups"
         :has-failed-jobs="hasFailedJobs"
@@ -183,13 +181,6 @@ const headerTitle = computed(() => {
   })
 })
 
-const concurrentWorkflowCount = computed(
-  () => executionStore.runningWorkflowCount
-)
-const showConcurrentIndicator = computed(
-  () => concurrentWorkflowCount.value > 1
-)
-
 const {
   selectedJobTab,
   selectedWorkflowFilter,