ci: use stable rust toolchain for rustls and skip installing the docs

Closes #16447

.github/workflows/linux.yml

@@ -560,7 +560,7 @@ jobs:
           cd $HOME
           curl -sSf --compressed https://sh.rustup.rs/ | sh -s -- -y
           source $HOME/.cargo/env
-          rustup toolchain install nightly
+          rustup toolchain install stable --profile minimal
 
       - name: 'build rustls'
         if: contains(matrix.build.install_steps, 'rustls') && steps.cache-rustls.outputs.cache-hit != 'true'