subversion: need SWIG 3.x

Closes #39929.

Signed-off-by: Chongyu Zhu <[email protected]>

Author: xu-cheng

Formula/subversion.rb

@@ -23,7 +23,7 @@ class Subversion < Formula
   depends_on :java => ["1.8+", :build]
   depends_on "pkg-config" => :build
   depends_on "scons" => :build # For Serf
-  depends_on "swig" => :build
+  depends_on "swig@3" => :build # https://issues.apache.org/jira/browse/SVN-4818
   depends_on "apr"
   depends_on "apr-util"