Change CentOS 7 documentation test to CentOS 8.

The CentOS 7 documentation test relies on PostgreSQL 9.5 which has been removed from the yum.p.o repository package. Switch the test to CentOS 8 to fix the immediate issue, but a decision on the PostgreSQL 9.5 documentation will need to be made before the next release.

.github/workflows/test.yml

@@ -36,8 +36,8 @@ jobs:
           # All unit tests (with coverage) on the newest gcc available
           - param: test --vm=f32 --param=c-only --param=tz=America/New_York
 
-          # RHEL/CentOS 7 documentation
-          - param: doc --vm=co7
+          # RHEL/CentOS 8 documentation
+          - param: doc --vm=co8
 
           # All integration tests
           - param: test --vm=co7 --param=module=mock --param=module=real

test/ci.pl

@@ -149,7 +149,7 @@ eval
 
     if ($ARGV[0] eq 'doc')
     {
-        if ($strVm eq VM_CO7)
+        if ($strVm eq VM_CO7 || $strVm eq VM_CO8)
         {
             processBegin('LaTeX install');
             processExec(