chore: Update mathlib revision, fixing a conflict (#467)

[This
commit](leanprover-community/mathlib4@ed4fde1#diff-54ef6c59abdddf67950b1ee785a0c22c7e03d04f9ad8cdb7cf1d336a72f4d850)
in mathlib4 moves `foldl_eq_foldr` to another module, so we need to
import it or the build fails with

```lean
error: Cslib/Computability/URM/Basic.lean:178:27: Unknown constant `List.foldl_eq_foldr`
```

This PR updates the lake manifest past this commit with `lake update
mathlib` and fixes the issue

Author: marcelolynch

Cslib/Computability/URM/Basic.lean

@@ -7,6 +7,7 @@ module
 
 public import Cslib.Computability.URM.Defs
 public import Mathlib.Data.List.MinMax
+public import Mathlib.Data.List.Fold
 
 /-! # URM Basic Lemmas
 

lake-manifest.json

@@ -5,7 +5,7 @@
    "type": "git",
    "subDir": null,
    "scope": "leanprover-community",
-   "rev": "1a37cd3c8e618022c5e78dee604c75c3c946a681",
+   "rev": "6ef8cc2731780be866bf243afcb7732f4da5f406",
    "name": "mathlib",
    "manifestFile": "lake-manifest.json",
    "inputRev": "master",
@@ -15,7 +15,7 @@
    "type": "git",
    "subDir": null,
    "scope": "leanprover-community",
-   "rev": "83e90935a17ca19ebe4b7893c7f7066e266f50d3",
+   "rev": "d11647e94d22ea0d9c503af4a63d814f89ea0323",
    "name": "plausible",
    "manifestFile": "lake-manifest.json",
    "inputRev": "main",
@@ -75,7 +75,7 @@
    "type": "git",
    "subDir": null,
    "scope": "leanprover-community",
-   "rev": "756e3321fd3b02a85ffda19fef789916223e578c",
+   "rev": "be1a02994ae681d2676c068ebac67a08bf708f96",
    "name": "batteries",
    "manifestFile": "lake-manifest.json",
    "inputRev": "main",