Revert "bazel: Use canonical reproducible load_bazlets rule"

This reverts commit a7246edf9d1c1fc536d405315c64c030bfaf93e4.

Since bazel v6.1.0 the warning about shallow_since has been removed
since it was determined [1] to be potentially harmful to build
performance and reliability.

[1] https://github.com/bazelbuild/bazel/issues/12857

Change-Id: I6003ae03511bdc7b5ba2cbb6b15b928bba18bfb5