Revert "[mlir][spirv] Fix int type declaration duplication when serializing" and follow up commits (#144773)
This reverts the following PRs:
* https://github.com/llvm/llvm-project/pull/143108
* https://github.com/llvm/llvm-project/pull/144538
* https://github.com/llvm/llvm-project/pull/144685
Reverting because this disabled tests when building without the llvm
spirv backend enabled.