component/postfix: Add support for Linux 6.

  INFO (echo "# Do not edit -- this file documents how Postfix was built for your machine."; /bin/sh makedefs) >makedefs.tmp
  INFO ATTENTION:
  INFO ATTENTION: Unknown system type: Linux 6.1.6-arch1-3
  INFO ATTENTION:
  INFO make: *** [Makefile.in:33: Makefiles] Error 1
  INFO make: *** [Makefile:22: makefiles] Error 2

component/postfix/buildout.cfg

@@ -20,6 +20,7 @@ location = @@LOCATION@@
 patch-options = -p1
 patches =
   ${:_profile_base_location_}/noroot.patch#05fc6333e05576ea8e5a49f27a6ef951
+  ${:_profile_base_location_}/linux-6.patch#08967a35249243eb06e46b1868e2dae2
 configure-command = make
 configure-options = makefiles CCARGS=${:configure-options-CCARGS} AUXLIBS=${:configure-options-AUXLIBS}
 configure-options-CCARGS = '-DUSE_SASL_AUTH -DUSE_CYRUS_SASL -DUSE_TLS -DHAS_PCRE -DHAS_DB -I${libdb:location}/include -I${pcre:location}/include -I${openssl:location}/include -I${cyrus-sasl:location}/include/sasl -I${libnsl:location}/include'

component/postfix/linux-6.patch

+--- a/makedefs	2022-01-23 21:53:41.000000000 +0100
++++ b/makedefs	2022-09-07 19:07:02.000000000 +0200
+@@ -627,7 +627,8 @@
+ 		: ${SHLIB_ENV="LD_LIBRARY_PATH=`pwd`/lib"}
+ 		: ${PLUGIN_LD="${CC-gcc} -shared"}
+ 		;;
+- Linux.[345].*)	SYSTYPE=LINUX$RELEASE_MAJOR
++    Linux.[3456].*)
++		SYSTYPE=LINUX$RELEASE_MAJOR
+ 		case "$CCARGS" in
+ 		 *-DNO_DB*) ;;
+ 		 *-DHAS_DB*) ;;
+--- a/src/util/sys_defs.h	2021-12-05 19:59:27.000000000 +0100
++++ b/src/util/sys_defs.h	2022-09-07 19:09:09.000000000 +0200
+@@ -751,7 +751,8 @@
+  /*
+   * LINUX.
+   */
+-#if defined(LINUX2) || defined(LINUX3) || defined(LINUX4) || defined(LINUX5)
++#if defined(LINUX2) || defined(LINUX3) || defined(LINUX4) || defined(LINUX5) \
++	|| defined(LINUX6)
+ #define SUPPORTED
+ #define UINT32_TYPE	unsigned int
+ #define UINT16_TYPE	unsigned short