Add uv_wrap.h to libisctest_la_SOURCES
uv_wrap.h is included in tcp_test.c and udp_test.c and therefore should
be listed in lib/isc/tests/Makefile.am, otherwise unit test run from
distribution tarball fails to compile:
tcp_test.c:37:10: fatal error: uv_wrap.h: No such file or directory
#include "uv_wrap.h"
^~~~~~~~~~~
udp_test.c:37:10: fatal error: uv_wrap.h: No such file or directory
#include "uv_wrap.h"
^~~~~~~~~~~Scheduled pipeline https://gitlab.isc.org/isc-projects/bind9/-/pipelines/58300.
Closes #2327 (closed)