chore: bump mathlib to 6cf3ab1, fix breaking changes (#547)

Bump `mathlib` dependency to
[6cf3ab1](leanprover-community/mathlib4@6cf3ab1):
chore: make argument in `zero_le`/`one_le` implicit (#38148)
(2026-04-29)
Previously at:
[6727686](leanprover-community/mathlib4@6727686):
ci(olean_report): use `lake env` instead of `lake exec` to invoke cache
binary (#38712) (2026-04-29)

Tracking issue: #546

---

This PR bumps `mathlib` to an identified incompatible (first-known-bad)
commit (`6cf3ab1`) so you can reproduce and fix the incompatibility
locally by checking out this branch.

_Opened automatically by
[downstream-reports/track-incompatibility](https://github.com/leanprover-community/downstream-reports)
via [this workflow
run](https://github.com/leanprover/cslib/actions/runs/25351406099)._

---------

Co-authored-by: mathlib-nightly-testing[bot] <mathlib-nightly-testing[bot]@users.noreply.github.com>
Co-authored-by: Chris Henson <chrishenson.net@gmail.com>

Author: mathlib-nightly-testing[bot]

Cslib/Computability/Automata/NA/Concat.lean

@@ -177,7 +177,7 @@ theorem finConcat_language_eq [Inhabited Symbol] :
     obtain ⟨ss, ⟨_, h_ωtr⟩, _⟩ := concat_run_exists h_xl1 h_run2
     #adaptation_note
     /-- A grind regression found moving to nightly-2026-03-31 (changes from lean#13166) -/
-    have h_mtr := LTS.OmegaExecution.extract_mTr h_ωtr (zero_le (xl1.length + xl2.length))
+    have h_mtr := LTS.OmegaExecution.extract_mTr h_ωtr (zero_le (a := xl1.length + xl2.length))
     simp [← append_append_ωSequence, extract_eq_drop_take,
       take_append_of_le_length, ← List.length_append] at h_mtr
     have : ss (xl1.length + xl2.length) = (ss.drop xl1.length) xl2.length := by grind

lake-manifest.json

@@ -5,10 +5,10 @@
    "type": "git",
    "subDir": null,
    "scope": "leanprover-community",
-   "rev": "672768680fb7e4eff7dac7ceca12bc3889fd60fd",
+   "rev": "6cf3ab1c11e19e328c2e535bdd32d66dc7842fb5",
    "name": "mathlib",
    "manifestFile": "lake-manifest.json",
-   "inputRev": "672768680fb7e4eff7dac7ceca12bc3889fd60fd",
+   "inputRev": "6cf3ab1c11e19e328c2e535bdd32d66dc7842fb5",
    "inherited": false,
    "configFile": "lakefile.lean"},
   {"url": "https://github.com/leanprover-community/plausible",

lakefile.toml

@@ -18,7 +18,7 @@ weak.linter.unicodeLinter = false
 [[require]]
 name = "mathlib"
 scope = "leanprover-community"
-rev = "672768680fb7e4eff7dac7ceca12bc3889fd60fd"
+rev = "6cf3ab1c11e19e328c2e535bdd32d66dc7842fb5"
 
 [[lean_lib]]
 name = "Cslib"