Retire custom toolchain for rustdocs build (#205)

.github/workflows/rustdocs.yml

@@ -4,6 +4,7 @@ on:
   push:
     branches:
       - main
+      - fix-doc-build
 
 # So github actions runner can publish the built docs to the gh-pages branch
 permissions:
@@ -23,14 +24,6 @@ jobs:
           sudo apt-get install -y protobuf-compiler
           protoc --version
 
-      - name: Install toolchain
-        uses: actions-rs/toolchain@v1
-        with:
-          profile: minimal
-          toolchain: nightly
-          target: wasm32-unknown-unknown
-          override: true
-
       - name: Build rustdocs
         uses: actions-rs/cargo@v1
         env: