Bump home-assistant/builder from 2021.03.4 to 2021.04.1 (#1971)

Bumps [home-assistant/builder](https://github.com/home-assistant/builder) from 2021.03.4 to 2021.04.1.
- [Release notes](https://github.com/home-assistant/builder/releases)
- [Commits](https://github.com/home-assistant/builder/compare/2021.03.4...b77028ab08315dd69807752d2f3e00b0f0f49786)

Signed-off-by: dependabot[bot] <support@github.com>

Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

.github/workflows/builder.yml

@@ -116,7 +116,7 @@ jobs:
 
       - name: Build ${{ matrix.addon }} add-on
         if: steps.check.outputs.build_arch == 'true'
-        uses: home-assistant/builder@2021.03.4
+        uses: home-assistant/builder@2021.04.1
         with:
           args: |
             ${{ env.BUILD_ARGS }} \