[dependabot.yml] Ignore vitest since it's updated manually (#32730)

.github/dependabot.yml

@@ -10,8 +10,10 @@ updates:
       # Updated manually to align with minimum supported Node version
       - dependency-name: "@types/node"
       # Updated manually to align with repo microsoft/typespec
-      - dependency-name: "typescript"
+      - dependency-name: "@vitest/coverage-v8"
       - dependency-name: "prettier"
+      - dependency-name: "vitest"
+      - dependency-name: "typescript"
       # Updated manually by the Liftr team
       - dependency-name: "@azure-tools/typespec-liftr-base"
       # minimatch@9 is the last version to support Node 18
@@ -43,7 +45,9 @@ updates:
       # Updated manually to align with minimum supported Node version
       - dependency-name: "@types/node"
       # Updated manually to align with repo microsoft/typespec
+      - dependency-name: "@vitest/coverage-v8"
       - dependency-name: "prettier"
+      - dependency-name: "vitest"
       # Points to "github:actions/github-script" since package isn't published to npmjs
       - dependency-name: "@types/github-script"
     # Leave the constraint if the original constraint allows the new version, otherwise, bump the constraint.