Update lean-toolchain for testing leanprover/lean4#8784

leanprover-community-mathlib4-bot · leanprover-community-mathlib4-bot · commit 9105bc7a7e42 · 2025-06-23T09:15:23.000Z
diff --git a/lean-toolchain b/lean-toolchain
@@ -1 +1 @@
-leanprover/lean4:nightly-2025-06-20
+leanprover/lean4-pr-releases:pr-release-8784-5fe9499

Original file line number	Diff line number	Diff line change
`@@ -1 +1 @@`
`1`		`-leanprover/lean4:nightly-2025-06-20`
	`1`	`+leanprover/lean4-pr-releases:pr-release-8784-5fe9499`