Revert "Set JULIA_PKGDIR before Julia ever starts up when building docs (#25009)"

This reverts commit 38ba1d0.

Author: vtjnash

doc/Makefile

@@ -7,7 +7,6 @@ SRCDIR           := $(abspath $(dir $(lastword $(MAKEFILE_LIST))))
 JULIAHOME        := $(abspath $(SRCDIR)/..)
 include $(JULIAHOME)/Make.inc
 JULIA_EXECUTABLE := $(call spawn,$(build_bindir)/julia)
-export JULIA_PKGDIR := $(abspath $(SRCDIR)/deps)
 
 .PHONY: help clean cleanall html pdf linkcheck doctest check deps deploy
 

doc/make.jl

@@ -1,10 +1,5 @@
 # Install dependencies needed to build the documentation.
-if ENV["JULIA_PKGDIR"] != joinpath(@__DIR__, "deps")
-    # We clobber package repositories here, so don't let the user hurt themselves
-    error("Must set JULIA_PKGDIR to $(joinpath(@__DIR__, "deps"))")
-else
-    info(ENV["JULIA_PKGDIR"])
-end
+ENV["JULIA_PKGDIR"] = joinpath(@__DIR__, "deps")
 Pkg.init()
 cp(joinpath(@__DIR__, "REQUIRE"), Pkg.dir("REQUIRE"); remove_destination = true)
 Pkg.update()