docs: add draftlog entry for substr to slice replacement

JBR-0100 · JBR-0100 · commit ff319469afb3 · 2025-12-04T04:22:11.000+05:30
diff --git a/draftlogs/7662_change.md b/draftlogs/7662_change.md
@@ -0,0 +1 @@
+ - Replace deprecated `String.substr()` with `String.slice()` [[#7662](https://github.com/plotly/plotly.js/pull/7662)]

Original file line number	Diff line number	Diff line change
`@@ -0,0 +1 @@`
	`1`	+ - Replace deprecated `String.substr()` with `String.slice()` [[#7662](https://github.com/plotly/plotly.js/pull/7662)]