Remove dynamic year generation from generator scripts, as required by
the Chromium C++ style guide.
The dynamic year values were replaced by the current year at the time
the file was created according to git log. The code to dynamically
generate the year was removed.
This patch also refreshes generated files and hashes.

Bug: angleproject:5516
Change-Id: I735028bccb5c83217e92c380538f1abf0a906b2c
Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/2690950
Commit-Queue: Lubosz Sarnecki <lubosz.sarnecki@collabora.com>
Commit-Queue: Jamie Madill <jmadill@chromium.org>
Reviewed-by: Jamie Madill <jmadill@chromium.org>
Reviewed-by: Geoff Lang <geofflang@chromium.org>