chore: import upstream snapshot with attribution

libs/text-splitters/tests/test_data/test_splitter.xslt

@@ -0,0 +1,9 @@
+<?xml version="1.0"?>
+<xsl:stylesheet version="1.0"
+    xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
+    <xsl:template match="node()|@*">
+        <xsl:copy>
+            <xsl:apply-templates select="node()|@*" />
+        </xsl:copy>
+    </xsl:template>
+</xsl:stylesheet>