Update toolchain to 1.70.0

tarpaulin's latest tag is still 0.25.2.

Signed-off-by: J Robert Ray <jrray@jrray.org>

Author: jrray

.github/workflows/rust.yml

@@ -12,7 +12,7 @@ jobs:
     runs-on: ubuntu-latest
     timeout-minutes: 30
     container:
-      image: rust:1.68.2
+      image: rust:1.70.0
       options: --security-opt seccomp=unconfined --privileged
     env:
       # Disable cnproc because we're in a container

.site/spi/.spdev.yaml

@@ -6,7 +6,7 @@ release_notes: |
 
 toolchain:
   - kind: Rust
-    toolchain: 1.68.2
+    toolchain: 1.70.0
     additional_toolchains:
       - nightly
   - kind: Shell