Make libs.poi an api dependency

df.writeExcel that returns Sheet won't work without this or explicit dependency on libs.poi in user project

Author: koperagen

dataframe-excel/build.gradle.kts

@@ -11,7 +11,7 @@ repositories {
 
 dependencies {
     api(project(":"))
-    implementation(libs.poi)
+    api(libs.poi)
     implementation(libs.poi.ooxml)
 
     implementation(libs.kotlin.datetimeJvm)