ci: explain why declared MSRV doesn't match actual MSRV

.github/workflows/check-and-build-and-test.yml

@@ -229,6 +229,13 @@ jobs:
           shared-key: ${{ matrix.supporteds.target }}-latest-variable
           cache-on-failure: "true"
 
-      - name: Verify MSRV (minimum supported Rust version)
+      - name: Verify declared MSRV (minimum supported Rust version)
+        id: verify
+        continue-on-error: true
         run: cargo msrv verify
         working-directory: ${{ matrix.crate_directory }}
+
+      - name: Report actual MSRV and reason for failing the declared version
+        if: steps.verify.outcome == "failure"
+        run: cargo msrv find && exit 1
+        working-directory: ${{ matrix.crate_directory }}