net-snmp: link client_intf.so against our custom-built OpenSSL

The Python extension (client_intf.so) was linking against system
libcrypto.so.1.1. Two-part fix:

1. Add @openssl to deps and pass --with-openssl=$$EXT_BUILD_DEPS/openssl
   so net-snmp's configure uses our OpenSSL for the main library build.

2. Pass LDFLAGS="-L$$EXT_BUILD_DEPS/openssl/lib" when invoking setup.py
   in the postfix_script. The setup.py reads library names from
   net-snmp-config --libs but only net-snmp's own build dir ends up in
   library_dirs — OpenSSL's lib dir is silently dropped. The LDFLAGS
   env var ensures the linker finds our libcrypto.so.3 first.

CMK-33658

Change-Id: Id56c3ea5ba037c246390b65a36c5db6bdc6df296
(cherry picked from commit 4899d32)
(cherry picked from commit de9fc3c)
(cherry picked from commit ded4cd9)

Author: nigelgbanks

omd/packages/net-snmp/BUILD.net-snmp.bazel

@@ -26,6 +26,7 @@ configure_make(
         "--with-defaults",
         "--disable-scripts",
         '--with-mibdirs="\\\\$$\\$$HOME/local/share/snmp/mibs:\\\\$$\\$$HOME/share/snmp/mibs:/usr/share/snmp/mibs"',
+        "--with-openssl=$EXT_BUILD_DEPS/openssl",
     ],
     copts = [
         "-I$BUILD_TMPDIR/include",
@@ -86,7 +87,9 @@ configure_make(
         tar xf ${PYTHON_MODULES_TAR} -C $(dirname ${PYTHON_MODULES_TAR});
         mkdir -p lib/python
         cd python && \
-            CFLAGS="-Wno-incompatible-pointer-types" ${EXT_BUILD_DEPS}/python/bin/python3 setup.py install \
+            CFLAGS="-Wno-incompatible-pointer-types" \
+            LDFLAGS="-L${EXT_BUILD_DEPS}/openssl/lib" \
+            ${EXT_BUILD_DEPS}/python/bin/python3 setup.py install \
                 --basedir=.. \
                 --root=${INSTALLDIR} \
                 --prefix='' \
@@ -108,7 +111,10 @@ configure_make(
         "-C man DESTDIR='/' install",
         "-C mibs DESTDIR='/' mibsinstall",
     ],
-    deps = ["@python"],
+    deps = [
+        "@openssl",
+        "@python",
+    ],
 )
 
 genrule(