Remove outdated wrong information about Module's qualified name access.

[benibilme]

Document of 1.10 has outdated information as discussed at Julia forum. Following code contradicts with the documentation.

julia> module A data=1 end
Main.A
julia> A.data=2
2
julia> A.data
2

Julia 1.10 module documentation Qualified Names Section

Within a module, a variable name can be “reserved” without assigning to it by declaring it as global x. This prevents name conflicts for globals initialized after load time. The syntax M.x = y does not work to assign a global in another module; global assignment is always module-local.

Julia Version 1.10.0
Commit 3120989f39b (2023-12-25 18:01 UTC)
Build Info:
  Official https://julialang.org/ release
Platform Info:
  OS: Linux (x86_64-linux-gnu)
  CPU: 8 × Intel(R) Core(TM) i5-8265U CPU @ 1.60GHz
  WORD_SIZE: 64
  LIBM: libopenlibm
  LLVM: libLLVM-15.0.7 (ORCJIT, skylake)
  Threads: 1 on 8 virtual cores
Environment:
  LD_PRELOAD = /usr/lib/gcc/x86_64-pc-linux-gnu/13.2.1/../../../../lib/libstdc++.so

[vtjnash]

Seems to be similar to #53170, but in doc/src/manual/modules.md instead of doc/src/manual/variables-and-scoping.md