build(deps): pin dependency vitest to 2.1.8 (#10751)

This PR contains the following updates:

| Package | Type | Update | Change |
|---|---|---|---|
| [vitest](https://redirect.github.com/vitest-dev/vitest)
([source](https://redirect.github.com/vitest-dev/vitest/tree/HEAD/packages/vitest))
| devDependencies | pin | [`^2.1.6` ->
`2.1.8`](https://renovatebot.com/diffs/npm/vitest/2.1.8/2.1.8) |

Add the preset `:preserveSemverRanges` to your config if you don't want
to pin your dependencies.

---

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Co-authored-by: renovate[bot] <29139614+renovate[bot]@users.noreply.github.com>

packages/calcite-components/package.json

@@ -89,7 +89,7 @@
   "devDependencies": {
     "@esri/calcite-design-tokens": "3.0.0-next.2",
     "@esri/eslint-plugin-calcite-components": "2.0.0-next.1",
-    "vitest": "^2.1.6"
+    "vitest": "2.1.8"
   },
   "volta": {
     "extends": "../../package.json"