Enable ccache for NetBSD and OpenBSD as well.

.gitlab-ci.yml

@@ -17,12 +17,13 @@ include:
       os: 'openbsd'
       platform: 'amd64'
       tagname: 'OpenBSD'
+      build_flags: 'CC="ccache cc" CXX="ccache c++" RELEASE=1'
   - local: '.gitlab-ci-unix.yml'
     inputs:
       os: 'netbsd'
       platform: 'amd64'
       tagname: 'NetBSD'
-      build_flags: 'RELEASE=1 USE_SYSTEM_CURSES=1'
+      build_flags: 'CC="ccache cc" CXX="ccache c++" RELEASE=1 USE_SYSTEM_CURSES=1'
   - local: '.gitlab-ci-unix.yml'
     inputs:
       os: 'freebsd'