component/pcre2: disable optional features

prevent auto-detection from linking against system libraries when they
are available.

component/pcre2/buildout.cfg

@@ -14,3 +14,7 @@ configure-options =
   -DCMAKE_INSTALL_PREFIX=@@LOCATION@@
   -DPCRE2_BUILD_PCRE2_16=ON
   -DPCRE2_BUILD_PCRE2_32=ON
+  -DPCRE2_SUPPORT_LIBBZ2=OFF
+  -DPCRE2_SUPPORT_LIBZ=OFF
+  -DPCRE2_SUPPORT_LIBEDIT=OFF
+  -DPCRE2_SUPPORT_LIBREADLINE=OFF