build: update zlib to 1.12.3 (#206)

zlib 1.12.2 was pulled due to https://nvd.nist.gov/vuln/detail/CVE-2022-37434
and is no longer available. This breaks the build, and prevents version
release. Update to 1.12.3 to allow the build to work.

Makefile

@@ -2025,8 +2025,8 @@ LIB_JAVADOCS_JAR = $(PROJECT_NAME)jni-$(LIB_JAVA_VERSION)-javadoc.jar
 LIB_SOURCES_JAR = $(PROJECT_NAME)jni-$(LIB_JAVA_VERSION)-sources.jar
 SHA256_CMD = sha256sum
 
-ZLIB_VER ?= 1.2.12
-ZLIB_SHA256 ?= 91844808532e5ce316b3c010929493c0244f3d37593afd6de04f71821d5136d9
+ZLIB_VER ?= 1.2.13
+ZLIB_SHA256 ?= b3a24de97a8fdbc835b9833169501030b8977031bcb54b3b3ac13740f846ab30
 ZLIB_DOWNLOAD_BASE ?= http://zlib.net
 BZIP2_VER ?= 1.0.8
 BZIP2_SHA256 ?= ab5a03176ee106d3f0fa90e381da478ddae405918153cca248e682cd0c4a2269