esp-idf: Fix build by pinning to Rust 1.88

1.89 and later have difficulties compiling

Author: tronical

.github/workflows/ci.yaml

@@ -623,6 +623,7 @@ jobs:
                   default: true
                   buildtargets: esp32
                   ldproxy: false
+                  version: "1.88.0"
             - uses: Swatinem/rust-cache@v2
             - name: Build and Test Printer demo
               shell: bash

.github/workflows/nightly_tests.yaml

@@ -24,6 +24,7 @@ jobs:
                   default: true
                   buildtargets: esp32
                   ldproxy: false
+                  version: "1.88.0"
             - uses: Swatinem/rust-cache@v2
             - name: Build and Test Printer demo
               shell: bash