Remove an untracked file from zlib that we shouldn't have included

libz/zlib.pc

@@ -1,13 +0,0 @@
-prefix=/usr/local
-exec_prefix=${prefix}
-libdir=${exec_prefix}/lib
-sharedlibdir=${libdir}
-includedir=${prefix}/include
-
-Name: zlib
-Description: zlib compression library
-Version: 1.2.11
-
-Requires:
-Libs: -L${libdir} -L${sharedlibdir} -lz
-Cflags: -I${includedir}