python3: Link against keg_only sqlite

Fixes Homebrew/homebrew#17765.

Closes Homebrew/homebrew#17788.

Signed-off-by: Adam Vandenberg <flangy@gmail.com>

Formula/python3.rb

@@ -154,8 +154,8 @@ class Python3 < Formula
   def distutils_fix_superenv(args)
     if superenv?
       # To allow certain Python bindings to find brewed software:
-      cflags = "CFLAGS=-I#{HOMEBREW_PREFIX}/include"
-      ldflags = "LDFLAGS=-L#{HOMEBREW_PREFIX}/lib"
+      cflags = "CFLAGS=-I#{HOMEBREW_PREFIX}/include -I#{Formula.factory('sqlite').opt_prefix}/include"
+      ldflags = "LDFLAGS=-L#{HOMEBREW_PREFIX}/lib -L#{Formula.factory('sqlite').opt_prefix}/lib"
       unless MacOS::CLT.installed?
         # Help Python's build system (distribute/pip) to build things on Xcode-only systems
         # The setup.py looks at "-isysroot" to get the sysroot (and not at --sysroot)