Minor CI changes:

- Add --enable-reduced-exports test.
- test running apachectl -V in the TEST_INSTALL case
- test running httpd -V in the SKIP_TESTING case
- rejig to exit if SKIP_TESTING, un-nest the if block around testing
  (no functional change from this part)

Github: closes #405


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@1915513 13f79535-47bb-0310-9956-ffa450edef68

.github/workflows/linux.yml

@@ -248,6 +248,11 @@ jobs:
               TEST_INSTALL=1
               TEST_MOD_TLS=1
               CLEAR_CACHE=1
+          - name: Configured w/reduced exports
+            config: --enable-reduced-exports --enable-maintainer-mode
+            env: |
+              SKIP_TESTING=1
+              TEST_INSTALL=1
           # -------------------------------------------------------------------------
           ### TODO if: *condition_not_24x
           ### TODO: Fails because :i386 packages are not being found.