build: bump rust to latest stable (#14)

Signed-off-by: Iman Enami <44609233+imanenami@users.noreply.github.com>

Author: imanenami

charmcraft.yaml

@@ -57,7 +57,7 @@ parts:
       - pkg-config  # Needed to build cryptography
       - rustup      # Needed to build Python dependencies with Rust
     override-build: |
-      rustup default 1.87.0
+      rustup default 1.93.1
       craftctl default
       # Include requirements.txt in *.charm artifact for easier debugging
       cp requirements.txt "$CRAFT_PART_INSTALL/requirements.txt"