Bug 40083: Make remote_mktemp create directory with mode 0755

In order to make the permission on out/$project be 0755 (see tor-browser-build#41418), change the permission to 0755 on directories created by remote_mktemp.

I checked by rebuilding manual in tor-browser-build that with this change, the permission on directory out/manual is now 0755.

/closes #40083 (closed)

requested review from @morgan

assigned to @boklm

mentioned in issue tor-browser-build#41418

approved this merge request

merged