remove .jl extension in Pkg.update (#23214)

* remove .jl extension in Pkg.update

* add test

Author: fredrikekre

base/pkg/pkg.jl

@@ -225,7 +225,7 @@ optimal set of packages versions.
 Without arguments, updates all installed packages. When one or more package names are provided as
 arguments, only those packages and their dependencies are updated.
 """
-update(upkgs::AbstractString...) = cd(Entry.update,Dir.getmetabranch(),Set{String}([upkgs...]))
+update(upkgs::AbstractString...) = cd(Entry.update,Dir.getmetabranch(),Set{String}(splitjl.([upkgs...])))
 
 """
     resolve()

test/pkg.jl

@@ -588,6 +588,7 @@ end
         Pkg.add("Example.jl")
         @test [keys(Pkg.installed())...] == ["Example"]
         iob = IOBuffer()
+        Pkg.update("Example.jl")
         Pkg.checkout("Example.jl")
         Pkg.status("Example.jl", iob)
         str = chomp(String(take!(iob)))