[Internal] Clean up comments in library resource (#4015)

## Changes
<!-- Summary of your changes that are easy to understand -->
- Clean up undeleted comments

## Tests
<!-- 
How is this tested? Please see the checklist below and also describe any
other relevant tests
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- [x] `make test` run locally
- [x] relevant change in `docs/` folder
- [x] covered with integration tests in `internal/acceptance`
- [x] relevant acceptance tests are passing
- [x] using Go SDK

Author: edwardfeng-db

internal/providers/pluginfw/resources/library/resource_library.go

@@ -73,14 +73,6 @@ func (r *LibraryResource) Schema(ctx context.Context, req resource.SchemaRequest
 	resp.Schema = schema.Schema{
 		Description: "Terraform schema for Databricks Library",
 		Attributes: tfschema.ResourceStructToSchemaMap(LibraryExtended{}, func(c tfschema.CustomizableSchema) tfschema.CustomizableSchema {
-			// c.AddPlanModifier(stringplanmodifier.RequiresReplace(), "cluster_id")
-			// c.AddPlanModifier(objectplanmodifier.RequiresReplace(), "cran")
-			// c.AddPlanModifier(stringplanmodifier.RequiresReplace(), "egg")
-			// c.AddPlanModifier(stringplanmodifier.RequiresReplace(), "jar")
-			// c.AddPlanModifier(objectplanmodifier.RequiresReplace(), "maven")
-			// c.AddPlanModifier(objectplanmodifier.RequiresReplace(), "pypi")
-			// c.AddPlanModifier(stringplanmodifier.RequiresReplace(), "requirements")
-			// c.AddPlanModifier(stringplanmodifier.RequiresReplace(), "whl")
 			for field, attribute := range c.ToAttributeMap() {
 				switch attribute.(type) {
 				case tfschema.StringAttributeBuilder: