symlink throws wrong exception on Windows

[KristofferC]

MWE (on a non-admin Julia):

julia> touch("foo")
"foo"

julia> symlink("foo", "bar")
ERROR: MethodError: no method matching !(::Int64)
Closest candidates are:
  !(::Bool) at bool.jl:33
  !(::Function) at operators.jl:969
  !(::Missing) at missing.jl:101
Stacktrace:
 [1] symlink(target::String, link::String; dir_target::Bool)
   @ Base.Filesystem .\file.jl:1042
 [2] symlink(target::String, link::String)
   @ Base.Filesystem .\file.jl:1010
 [3] top-level scope
   @ REPL[20]:1

julia/base/file.jl

Lines 1056 to 1058 in cc45b99

	if !(flags & UV_FS_SYMLINK_JUNCTION) && err == UV__EPERM
	msg = "On Windows, creating symlinks requires Administrator privileges.\n$msg"
	end

Introduced in #39491.

Tar.jl expects this to throw a IOError when it fails: https://github.com/JuliaIO/Tar.jl/blob/37766a22f5a6ac9f07022d83debd5db7d7a4b896/src/Tar.jl#L21-L33

Causes: #40000, #40022, #40021.