update release date to actual released date

sksat · sksat · commit f21eb2dba0d3 · 2023-09-20T08:19:21.000+09:00
diff --git a/RELEASES.md b/RELEASES.md
@@ -1,4 +1,4 @@
-Version 1.72.1 (2023-09-14)
+Version 1.72.1 (2023-09-19)
 ===========================
 
 - [Adjust codegen change to improve LLVM codegen](https://github.com/rust-lang/rust/pull/115236)

Original file line number	Diff line number	Diff line change
`@@ -1,4 +1,4 @@`
`1`		`-Version 1.72.1 (2023-09-14)`
	`1`	`+Version 1.72.1 (2023-09-19)`
`2`	`2`	`===========================`
`3`	`3`
`4`	`4`	`- [Adjust codegen change to improve LLVM codegen](https://github.com/rust-lang/rust/pull/115236)`