This slightly degrades the performance of CJS export analysis on
subsequent runs because I changed it to no longer cache in the DENO_DIR
with this PR (denort now properly has no idea about the DENO_DIR). We'll
have to change it to embed this data in the binary and that will also
allow us to get rid of swc in denort (will do that in a follow-up PR).
(cherry picked from commit 57dd66ec3d)
Fixes https://github.com/denoland/deno/issues/24749
Runs a server that just returns the header tarball and checksum, and
sets the `NODEJS_ORG_MIRROR` env var so that `node-gyp` uses it instead
of `nodejs.org`
