we want to test the installed extension, so don't source from the build tree

--- a/test/expected/init_1.out
+++ b/test/expected/init_1.out
@@ -1,11 +1 @@
-\i plsh.sql
-CREATE FUNCTION plsh_handler() RETURNS language_handler
-    AS '$libdir/plsh'
-    LANGUAGE C;
-CREATE FUNCTION plsh_validator(oid) RETURNS void
-    AS '$libdir/plsh'
-    LANGUAGE C;
-CREATE LANGUAGE plsh
-    HANDLER plsh_handler
-    VALIDATOR plsh_validator;
-COMMENT ON LANGUAGE plsh IS 'PL/sh procedural language';
+CREATE EXTENSION plsh;
--- a/test/sql/init.sql
+++ b/test/sql/init.sql
@@ -1 +1 @@
-\i plsh.sql
+CREATE EXTENSION plsh;
