find versioned abseil libraries

Index: setup.py
--- setup.py.orig
+++ setup.py
@@ -402,8 +402,10 @@ if BUILD_WITH_SYSTEM_RE2:
     EXTENSION_LIBRARIES += ("re2",)
 if BUILD_WITH_SYSTEM_ABSL:
     EXTENSION_LIBRARIES += tuple(
-        lib.stem[3:]
-        for lib in sorted(pathlib.Path("/usr").glob("lib*/libabsl_*.so"))
+        sorted(set(
+        lib.stem[3:].split(".", maxsplit=1)[0]
+        for lib in sorted(pathlib.Path("/usr/local/lib").glob("libabsl_*.so.*"))
+        ))
     )
 
 DEFINE_MACROS = (("_WIN32_WINNT", 0x600),)
