Update lean-toolchain for testing leanprover/lean4#8420

leanprover-community-mathlib4-bot · leanprover-community-mathlib4-bot · commit fedab5fe87cf · 2025-05-30T10:27:05.000Z
diff --git a/lean-toolchain b/lean-toolchain
@@ -1 +1 @@
-leanprover/lean4:nightly-2025-05-29
+leanprover/lean4-pr-releases:pr-release-8420

Original file line number	Diff line number	Diff line change
`@@ -1 +1 @@`
`1`		`-leanprover/lean4:nightly-2025-05-29`
	`1`	`+leanprover/lean4-pr-releases:pr-release-8420`