Enforce 1.85 toolchain in Dart/Python workflows

It was previously being overriden by rust-toolchain.toml

Author: spacebear21

.github/workflows/dart.yml

@@ -5,6 +5,12 @@ on:
       - payjoin-ffi/**
 
 jobs:
+  env:
+    # Override the value from the rust-toolchain file
+    # This is necessary because even though the correct toolchain
+    # is explicitly specified for the rust-toolchain action,
+    # rustup honors the rust-toolchain file over the default
+    RUSTUP_TOOLCHAIN: 1.85
   test:
     runs-on: ${{ matrix.os }}
     defaults:

.github/workflows/python.yml

@@ -5,6 +5,12 @@ on:
       - payjoin-ffi/**
 
 jobs:
+  env:
+    # Override the value from the rust-toolchain file
+    # This is necessary because even though the correct toolchain
+    # is explicitly specified for the rust-toolchain action,
+    # rustup honors the rust-toolchain file over the default
+    RUSTUP_TOOLCHAIN: 1.85
   build-wheels-and-test:
     name: "Build and test Linux"
     runs-on: ubuntu-latest