ci/nightly: Track and test dependencies' 'test-next' branch

parsec-tool depends on several repositories under the parallaxsecond
organization.

Currently, when testing the main branch of parsec-tool, fixed versions
of the latest released crates of those repositories are being used.
A problem may arise when there is a change introduced in the
main/'test-next' branch of those repositories that would break
parsec-tool when updating/incorporating that change. This is currently
not being tested in our CI.
As parsec-tool release is dependent on having published the
dependencies' crates, there are issues that will not be caught until
the publishing of said crates.

* Add a nightly job that uses ci.sh --test-next-branch-tracking to
  test the test-next release branches of parallaxsecond repositories
  and spot issues before release. These job makes use of previously
  defined re-usable actions.

Signed-off-by: Tomás González <[email protected]>

.github/workflows/nightly.yml

@@ -42,3 +42,20 @@ jobs:
         run: cargo install cargo-audit
       - name: Execute cargo audit
         run: cargo audit
+
+  build-next:
+    name: Execute CI script with next branch
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v3
+        with:
+          ref: "${{ github.event.inputs.rev }}"
+      - name: Install Rust MSRV
+        uses: actions-rust-lang/setup-rust-toolchain@v1
+        with:
+          toolchain: 1.66.0
+          rustflags: ""
+      - name: Execute CI script with next branch
+        uses: ./.github/actions/ci_script
+        with:
+          ci-flags: "--test-next-branch-tracking"