Bump actions/download-artifact from 4.1.3 to 4.1.8

Bumps [actions/download-artifact](https://github.com/actions/download-artifact) from 4.1.3 to 4.1.8.
- [Release notes](https://github.com/actions/download-artifact/releases)
- [Commits](actions/download-artifact@87c5514...fa0a91b)

---
updated-dependencies:
- dependency-name: actions/download-artifact
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

Signed-off-by: dependabot[bot] <[email protected]>

.github/workflows/tf-plan-apply.yml

@@ -64,7 +64,7 @@ jobs:
           role-to-assume: arn:aws:iam::${{ vars.AWS_ACCOUNT_ID }}:role/apply
           aws-region: ${{ vars.AWS_REGION }}
       - name: Download plan
-        uses: actions/download-artifact@87c55149d96e628cc2ef7e6fc2aab372015aec85 # v4
+        uses: actions/download-artifact@fa0a91b85d4f404e444e00e005971372dc801d16 # v4
         with:
           name: tfplan
           path: tf