security/zeek: Clean up USES=python

- While I'm here, fix PLIST

====> Checking for pkg-plist issues (check-plist)
===> Parsing plist
===> Checking for items in STAGEDIR missing from pkg-plist
Error: Orphaned: @dir lib/%%ZEEKUSER%%/plugins
Error: Orphaned: @dir lib/%%ZEEKUSER%%/spicy
===> Checking for items in pkg-plist which are not in STAGEDIR
===> Error: Plist issues found.
*** Error code 1

Approved by:	portmgr (blanket)
With hat:	python

security/zeek/Makefile

@@ -20,7 +20,7 @@ LIB_DEPENDS=	libcares.so:dns/c-ares
 RUN_DEPENDS=	c-ares>=1.18.1:dns/c-ares
 
 USES=		bison cmake compiler:c++17-lang cpe gettext-runtime perl5 \
-		python:3.7+ shebangfix ssl
+		python shebangfix ssl
 
 USE_LDCONFIG=	yes
 

security/zeek/pkg-plist

@@ -1233,6 +1233,7 @@ lib/libparaglob.a
 %%SPICY%%lib/libspicy-rt-debug.a
 %%SPICY%%lib/libspicy-rt.a
 %%SPICY%%lib/libspicy.so
+@dir lib/zeek/plugins
 lib/zeek/python/SubnetTree.py
 lib/zeek/python/_SubnetTree.so
 lib/zeek/python/broker/__init__.py
@@ -1283,6 +1284,7 @@ lib/zeek/python/zeekctl/plugins/lb_pf_ring.py
 lib/zeek/python/zeekctl/plugins/ps.py
 lib/zeek/python/zeekctl/plugins/zeek_port_warning.py
 lib/zeek/python/zeekctl/plugins/zzz_af_packet.py
+@dir lib/zeek/spicy
 %%ZEEKCTL%%man/man1/trace-summary.1.gz
 man/man1/zeek-cut.1.gz
 man/man8/zeek.8.gz