Bump actions/download-artifact from 7 to 8

Bumps [actions/download-artifact](https://github.com/actions/download-artifact) from 7 to 8.
- [Release notes](https://github.com/actions/download-artifact/releases)
- [Commits](actions/download-artifact@v7...v8)

---
updated-dependencies:
- dependency-name: actions/download-artifact
  dependency-version: '8'
  dependency-type: direct:production
  update-type: version-update:semver-major
...

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

Author: dependabot[bot]

.github/workflows/pull-request-checks.yaml

@@ -174,7 +174,7 @@ jobs:
       - name: Confirm z3 solver is available and log the version installed
         run: z3 --version
       - name: Get the ebmc binary
-        uses: actions/download-artifact@v7
+        uses: actions/download-artifact@v8
         with:
           name: ebmc-binary
           path: ebmc
@@ -208,7 +208,7 @@ jobs:
       - name: Confirm ltl2tgba is available and log the version installed
         run: ltl2tgba --version
       - name: Get the ebmc binary
-        uses: actions/download-artifact@v7
+        uses: actions/download-artifact@v8
         with:
           name: ebmc-binary
           path: ebmc
@@ -228,7 +228,7 @@ jobs:
     steps:
       - uses: actions/checkout@v6
       - name: Get the ebmc binary
-        uses: actions/download-artifact@v7
+        uses: actions/download-artifact@v8
         with:
           name: ebmc-binary
           path: ebmc
@@ -237,7 +237,7 @@ jobs:
       - name: ebmc on Hazard3
         run: PATH=$PATH:$PWD/ebmc examples/Hazard3/Hazard3-ebmc.sh
       - name: Get the vlindex binary
-        uses: actions/download-artifact@v7
+        uses: actions/download-artifact@v8
         with:
           name: vlindex-binary
           path: vlindex
@@ -512,17 +512,17 @@ jobs:
       - name: Confirm z3 solver is available and log the version installed
         run: z3 --version
       - name: Get the ebmc binary
-        uses: actions/download-artifact@v7
+        uses: actions/download-artifact@v8
         with:
           name: ebmc-binary
           path: bin
       - name: Get the hw-cbmc binary
-        uses: actions/download-artifact@v7
+        uses: actions/download-artifact@v8
         with:
           name: hw-cbmc-binary
           path: bin
       - name: Get the vlindex binary
-        uses: actions/download-artifact@v7
+        uses: actions/download-artifact@v8
         with:
           name: vlindex-binary
           path: bin