ci: Add job to check that sqlx builds with its declared minimum dependencies

Signed-off-by: Joshua Potts <8704475+iamjpotts@users.noreply.github.com>

.github/workflows/sqlx.yml

@@ -50,6 +50,16 @@ jobs:
           --features all-databases,_unstable-all-types,runtime-${{ matrix.runtime }},tls-${{ matrix.tls }},macros
           --target-dir target/beta/
 
+  check-minimal-versions:
+    name: Check build using minimal versions
+    runs-on: ubuntu-22.04
+    steps:
+      - uses: actions/checkout@v2
+      - run: rustup update
+      - run: rustup toolchain install nightly
+      - run: cargo +nightly generate-lockfile -Z minimal-versions
+      - run: cargo build --all-features
+
   test:
     name: Unit Test
     runs-on: ubuntu-22.04