build: Fix --build-3rdparty on cmake 4.x

Add -DCMAKE_POLICY_VERSION_MINIMUM=3.5 when building dependencies
with cmake, so that the build doesn't fail when we build old
dependencies with new cmake.

While this is not guaranteed to work in general case, it seems to
work fine with all our dependencies.

(cherry picked from commit 7b8392c)

Author: gavv

scripts/scons_helpers/build-3rdparty.py

@@ -281,6 +281,11 @@ def _getvar(var, default):
             '-DCMAKE_C_FLAGS_RELEASE:STRING=' + quote(' '.join(cc_flags)),
         ]
 
+    # compatibility with older cmake files
+    args += [
+        '-DCMAKE_POLICY_VERSION_MINIMUM=3.5',
+    ]
+
     execute(ctx, 'cmake ' + src_dir + ' ' + ' '.join(args))
 
 def execute_cmake_build(ctx):