Format total count of runners in tabs by locale

What does this MR do and why?

This change formats the total count of each type of runner in the tabs with a thousands separator according to the current user locale.

Changelog: changed

Screenshots or screen recordings

before	after (mocked)

How to set up and validate locally

‼ I used mock numbers to display the formatting

1. With many runners available... or with mock data:

Diff to change data

diff --git a/app/assets/javascripts/runner/admin_runners/admin_runners_app.vue b/app/assets/javascripts/runner/admin_runners/admin_runners_app.vue
index 3366942f6ad..844186537ca 100644
--- a/app/assets/javascripts/runner/admin_runners/admin_runners_app.vue
+++ b/app/assets/javascripts/runner/admin_runners/admin_runners_app.vue
@@ -102,6 +102,9 @@ export default {
       variables() {
         return this.countVariables;
       },
+      update(data) {
+        return 63153;
+      },
     },
     instanceRunnersCount: {
       ...runnersCountSmartQuery,
@@ -111,6 +114,9 @@ export default {
           type: INSTANCE_TYPE,
         };
       },
+      update(data) {
+        return 23;
+      },
     },
     groupRunnersCount: {
       ...runnersCountSmartQuery,
@@ -120,6 +126,9 @@ export default {
           type: GROUP_TYPE,
         };
       },
+      update(data) {
+        return 2054;
+      },
     },
     projectRunnersCount: {
       ...runnersCountSmartQuery,
@@ -129,6 +138,9 @@ export default {
           type: PROJECT_TYPE,
         };
       },
+      update(data) {
+        return 61076;
+      },
     },
   },
   computed: {

2. Visit the admin runners page at http://gdk.test:3000/admin/runners.

MR acceptance checklist

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• I have evaluated the MR acceptance checklist for this MR.

Related to #346919 (closed)