CI: Use latest SQLAlchemy release on GHA's "nightly" job

Author: amotl

.github/workflows/nightly.yml

@@ -18,7 +18,7 @@ jobs:
         os: ['ubuntu-20.04', 'ubuntu-22.04', 'macos-11', 'macos-12']
         python-version: ['3.7', '3.8', '3.9', '3.10']
         cratedb-version: ['nightly']
-        sqla-version: ['1.4.37']
+        sqla-version: ['latest']
       fail-fast: false
     env:
       CRATEDB_VERSION: ${{ matrix.cratedb-version }}

devtools/setup_ci.sh

@@ -19,7 +19,11 @@ function main() {
   echo "Invoking tests with CrateDB ${CRATEDB_VERSION} and SQLAlchemy ${SQLALCHEMY_VERSION}"
 
   # Install designated SQLAlchemy version.
-  pip install "sqlalchemy==${SQLALCHEMY_VERSION}"
+  if [ ${SQLALCHEMY_VERSION} = "latest" ]; then
+    pip install "sqlalchemy" --upgrade
+  else
+    pip install "sqlalchemy==${SQLALCHEMY_VERSION}"
+  fi
 
   # Replace CrateDB version.
   if [ ${CRATEDB_VERSION} = "nightly" ]; then