CI: setup_ci should run before bootstrap.sh

On the "nightly" runs, the test suite did not actually use CrateDB
nightly builds, but used the version defined in `versions.cfg` instead.

Author: amotl

.github/workflows/nightly.yml

@@ -36,12 +36,12 @@ jobs:
       - name: Invoke tests
         run: |
 
-          # Bootstrap environment.
-          source bootstrap.sh
-
           # Propagate build matrix information.
           ./devtools/setup_ci.sh
 
+          # Bootstrap environment.
+          source bootstrap.sh
+
           # Invoke validation tasks.
           flake8 src bin
           coverage run bin/test -vv1

.github/workflows/tests.yml

@@ -37,12 +37,12 @@ jobs:
       - name: Invoke tests
         run: |
 
-          # Bootstrap environment.
-          source bootstrap.sh
-
           # Propagate build matrix information.
           ./devtools/setup_ci.sh
 
+          # Bootstrap environment.
+          source bootstrap.sh
+
           # Invoke validation tasks.
           flake8 src bin
           coverage run bin/test -vv1