[CI] Ensure Move Tests are run when Move files change (MystenLabs#14479)

## Description

Move tests are run as part of the Rust tests for the Sui Framework, but
they should also be run when there are only Move changes.

Surfaced because a recent PR (MystenLabs#14429) Moved some Move tests causing CI
to fail on `main`, and this wasn't picked up because diff tests hadn't
been run.

## Test Plan

CI

.github/actions/diffs/action.yml

@@ -11,8 +11,8 @@ outputs:
     description: True when changes happened to the Move code
     value: "${{ steps.diff.outputs.isMove }}"
   isReleaseNotesEligible:
-    description: True when changes happened in Release Notes eligible paths 
-    value: "${{ steps.diff.outputs.isReleaseNotesEligible }}"    
+    description: True when changes happened in Release Notes eligible paths
+    value: "${{ steps.diff.outputs.isReleaseNotesEligible }}"
 
 runs:
   using: composite
@@ -42,6 +42,7 @@ runs:
           - 'crates/sui-framework-tests/**'
           - 'crates/sui_move/**'
           - 'Cargo.toml'
+          - 'examples/**'
           - 'sui_programmability/**'
         isReleaseNotesEligible:
           - 'crates/**'

.github/workflows/rust.yml

@@ -221,6 +221,22 @@ jobs:
       - name: check new tests for flakiness
         run: |
           scripts/simtest/stress-new-tests.sh
+
+  # This job ensures that Move unit tests are run if there are changes
+  # to Move code but not Rust code (If there are Rust changes, they
+  # will be run as part of a larger test suite).
+  move-test:
+    needs: diff
+    if: needs.diff.outputs.isRust == 'false' && needs.diff.outputs.isMove == 'true'
+    timeout-minutes: 10
+    runs-on: [ubuntu-ghcloud]
+    steps:
+      - uses: actions/checkout@v3
+      - uses: taiki-e/install-action@nextest
+      - name: Run move tests
+        run: |
+          cargo nextest run -p sui-framework-tests -- unit_tests::
+
   # # Disabled
   # rosetta-validation:
   #   needs: diff