Update RISC-V compilers in Nuttx compilation CI and spec test CI (#2756)

Update RISC-V compilers in Nuttx compilation CI and spec test CI
to test workflows.

Signed-off-by: Huang Qi <huangqi3@xiaomi.com>

.github/workflows/compilation_on_nuttx.yml

@@ -94,9 +94,9 @@ jobs:
       - name: Install RISC-V Compilers
         if: contains(matrix.nuttx_board_config, 'risc-v')
         run: |
-          curl -L -k https://static.dev.sifive.com/dev-tools/freedom-tools/v2020.12/riscv64-unknown-elf-toolchain-10.2.0-2020.12.8-x86_64-linux-ubuntu14.tar.gz > riscv.tar.gz
+          curl -L https://github.com/xpack-dev-tools/riscv-none-elf-gcc-xpack/releases/download/v12.3.0-1/xpack-riscv-none-elf-gcc-12.3.0-1-linux-x64.tar.gz > riscv.tar.gz
           tar xvf riscv.tar.gz
-          echo "$PWD/riscv64-unknown-elf-toolchain-10.2.0-2020.12.8-x86_64-linux-ubuntu14/bin" >> $GITHUB_PATH
+          echo "$PWD/xpack-riscv-none-elf-gcc-12.3.0-1/bin" >> $GITHUB_PATH
 
       - name: Install WASI-SDK
         run: |

.github/workflows/spec_test_on_nuttx.yml

@@ -52,9 +52,9 @@ jobs:
       - name: Install RISC-V Compilers
         if: contains(matrix.nuttx_board_config, 'risc-v')
         run: |
-          curl -L -k https://static.dev.sifive.com/dev-tools/freedom-tools/v2020.12/riscv64-unknown-elf-toolchain-10.2.0-2020.12.8-x86_64-linux-ubuntu14.tar.gz > riscv.tar.gz
+          curl -L https://github.com/xpack-dev-tools/riscv-none-elf-gcc-xpack/releases/download/v12.3.0-1/xpack-riscv-none-elf-gcc-12.3.0-1-linux-x64.tar.gz > riscv.tar.gz
           tar xvf riscv.tar.gz
-          echo "$PWD/riscv64-unknown-elf-toolchain-10.2.0-2020.12.8-x86_64-linux-ubuntu14/bin" >> $GITHUB_PATH
+          echo "$PWD/xpack-riscv-none-elf-gcc-12.3.0-1/bin" >> $GITHUB_PATH
 
       - name: Install WASI-SDK
         run: |