devdoc: fix markdown title link

[inkydragon]

Revert short title link introduced in #44300

Use the default generated long link to keep the URL on GitHub alive.

V:\julia\doc\src\devdocs\build\build.md
  19,15: dependencies](#required-build-tools-and-external-libraries). If you
  305,39: Then add all the [build dependencies](#required-build-tools-and-external-libraries), a console-based editor of your choice, `git`, and anything else you'll need (e.g., `gdb`, `rr`, etc). Pick a directory to work in and `git clone` Julia, check out the branch you wish to debug, and build Julia as usual.

V:\julia\doc\src\devdocs\build\linux.md
  7,48: * See also the [external dependencies](build.md#required-build-tools-and-external-libraries).

V:\julia\README.md
  86,92: dependencies](https://github.com/JuliaLang/julia/blob/master/doc/src/devdocs/build/build.md#required-build-tools-and-external-libraries) installed.