Fix nightly run CI

[TianlongLiang]

Manually git clone and install dependencies instead of using git action on Ubuntu 14.04 runner

[TianlongLiang]

As mentioned in this blog, GitHub actions will default use node20.

The problem is that node20 will require a more recent version of glibc and glibcxx than the Ubuntu 14.04 docker image provides, that's why build_iwasm_linux_gcc4_8 is failing those days.

Since we are using the GitHub provided runner, we have no control over the external node version like forks did in this issue, so I think temporarily replacing the GitHub action in build_iwasm_linux_gcc4_8 with normal commands would be a good solution

[TianlongLiang]

@loganek @yamt what do you guys think?

[yamt]

@loganek do you still need the ancient toolchain support?

[yamt]

looks reasonable to me

[wenyongh]

Thanks for Tianlong's effort, I merged the PR since we had better let nightly-run CI run every day. @loganek please upload another PR to enhance it if needed, thanks.