Avoid sandbox denial while attempting to generate PCH:
```
F: fopen_wr
S: deny
P: /usr/include/apr-1/apr.h.gch
A: /usr/include/apr-1/apr.h.gch
R: /usr/include/apr-1/apr.h.gch
C: /usr/libexec/gcc/x86_64-pc-linux-gnu/13/cc1 -quiet /usr/include/apr-1/apr.h -quiet -dM -dumpdir a- -dumpbase apr.h -dumpbase-ext .h -mtune=generic -march=x86-64 -o /tmp/ccfl5N0L.s --output-pch /usr/include/apr-1/apr.h.gch
```

Sent upstream by email on 2023-07-05.
--- a/lib/Apache2/Build.pm
+++ b/lib/Apache2/Build.pm
@@ -1502,7 +1502,7 @@ sub get_apr_config {
         };
     }
     else {
-        my @command = ($self->perl_config('cpp'), '-dM', $header);
+        my @command = ($self->perl_config('cpp'), '-E', '-dM', $header);
         open $fh, '-|', @command or do {
             error "Unable to preprocess $header with @command: $!";
             return undef;