Update Charon submodule to v0.1.69 (#4660)

Advance the Charon pin from v0.1.68 (63f7749d) to v0.1.69 (485bd36e),
the next step of the incremental effort to catch the pinned Charon up
with upstream (the endgame is dropping scripts/charon-patch.diff
entirely).

Charon v0.1.69 makes `Vector::elem_count` the way to obtain the number
of non-empty slots (`len` is removed); adapt the tuple-field-projection
translation in the LLBC backend accordingly.

Refresh scripts/charon-patch.diff so its hunks apply against the v0.1.69
sources (context-line drift only; the patch content is unchanged).

By submitting this pull request, I confirm that my contribution is made
under the terms of the Apache 2.0 and MIT licenses.

Co-authored-by: Kiro <kiro-agent@users.noreply.github.com>

Author: tautschnig

Cargo.lock

@@ -288,7 +288,7 @@ checksum = "f079e83a288787bcd14a6aea84cee5c87a67c5a3e660c30f557a3d24761b3527"
 
 [[package]]
 name = "charon"
-version = "0.1.68"
+version = "0.1.69"
 dependencies = [
  "annotate-snippets",
  "anstream 0.6.21",

charon

@@ -1873,7 +1873,7 @@ impl<'a, 'tcx> Context<'a, 'tcx> {
                             }
                         }
                         CharonTyKind::Adt(CharonTypeId::Tuple, genargs) => {
-                            let c_fprj = CharonFieldProjKind::Tuple(genargs.types.len());
+                            let c_fprj = CharonFieldProjKind::Tuple(genargs.types.elem_count());
                             current_ty = self.translate_ty(*ty);
                             c_provec.push((
                                 CharonProjectionElem::Field(c_fprj, c_fieldid),

kani-compiler/src/codegen_aeneas_llbc/mir_to_ullbc/mod.rs

@@ -1,21 +1,21 @@
 diff --git a/charon/Cargo.toml b/charon/Cargo.toml
-index d76c223c..0b354b1c 100644
+index cbba6280f..8b5b4ece8 100644
 --- a/charon/Cargo.toml
 +++ b/charon/Cargo.toml
 @@ -2,7 +2,7 @@
  name = "charon"
- version = "0.1.68"
+ version = "0.1.69"
  authors = ["Son Ho <hosonmarc@gmail.com>"]
 -edition = "2021"
 +edition = "2024"
  license = "Apache-2.0"
 
  [lib]
 diff --git a/charon/src/ids/vector.rs b/charon/src/ids/vector.rs
-index 141cabe3..37948679 100644
+index 24dd10839..3ef70b0bc 100644
 --- a/charon/src/ids/vector.rs
 +++ b/charon/src/ids/vector.rs
-@@ -254,7 +254,7 @@ where
+@@ -260,7 +260,7 @@ where
          self.iter_indexed().map(|(id, _)| id)
      }
 
@@ -25,7 +25,7 @@ index 141cabe3..37948679 100644
      }
 
 diff --git a/charon/src/transform/expand_associated_types.rs b/charon/src/transform/expand_associated_types.rs
-index 225da182..54370990 100644
+index 2b8a5d162..4716da208 100644
 --- a/charon/src/transform/expand_associated_types.rs
 +++ b/charon/src/transform/expand_associated_types.rs
 @@ -761,7 +761,7 @@ impl<'a> ComputeItemModifications<'a> {