GitHub Actions: fix running out of space on Ubuntu build workflow (#23)

Summary:
As per actions/runner-images#709 there started to be some issies with Ubuntu envs running out of space. This should fix it.

Also our Cargo builds use a lot of space, changing them to be non-incremental and removing debug symbols keeps the build fast, but greatly reduces the disk space usage leaving us enough space on GitHub Actions virtual machines.
Pull Request resolved: facebook/sapling#23

Reviewed By: farnz

Differential Revision: D22160020

Pulled By: lukaspiatkowski

fbshipit-source-id: c23393e310c15ebf5a18b80f0bb5f1f894d24849

build/fbcode_builder/getdeps/builder.py

@@ -1002,8 +1002,13 @@ def _build(self, install_dirs, reconfigure):
                 """\
 [build]
 target-dir = '''{}'''
+
 [net]
 git-fetch-with-cli = true
+
+[profile.dev]
+debug = false
+incremental = false
 """.format(
                     self.build_dir.replace("\\", "\\\\")
                 )