Update lean-toolchain for testing leanprover/lean4#8968

leanprover-community-mathlib4-bot · leanprover-community-mathlib4-bot · commit 7fec2b15df56 · 2025-06-26T16:29:09.000Z
diff --git a/lean-toolchain b/lean-toolchain
@@ -1 +1 @@
-leanprover/lean4:nightly-2025-06-26
+leanprover/lean4-pr-releases:pr-release-8968-af87540

Original file line number	Diff line number	Diff line change
`@@ -1 +1 @@`
`1`		`-leanprover/lean4:nightly-2025-06-26`
	`1`	`+leanprover/lean4-pr-releases:pr-release-8968-af87540`