Bump dlang-community/setup-dlang from 1.3.0 to 1.4.0 (#223)

Bumps [dlang-community/setup-dlang](https://github.com/dlang-community/setup-dlang) from 1.3.0 to 1.4.0.
- [Release notes](https://github.com/dlang-community/setup-dlang/releases)
- [Commits](dlang-community/setup-dlang@43589c2...2979e3e)

---
updated-dependencies:
- dependency-name: dlang-community/setup-dlang
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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

.github/workflows/tests.yml

@@ -17,7 +17,7 @@ jobs:
         dc: [dmd-latest, ldc-latest]
     steps:
       - uses: actions/checkout@b4ffde65f46336ab88eb53be808477a3936bae11
-      - uses: dlang-community/setup-dlang@43589c229861e1720e187a344c67dad1d9eefe4c
+      - uses: dlang-community/setup-dlang@2979e3ea011f6a234cd3a47dcbeb60f451c9635f
         with:
           compiler: ${{ matrix.dc }}
       - name: Run tests