Revert "glsl: remove restriction on unsized arrays in GLSL ES 3.10"

Revert "glsl: remove restriction on unsized arrays in GLSL ES 3.10"

This reverts commit adee54f8269c5e9f4fde91d19f0e465afc8f14d8.

Further down in the GLSL ES 3.10 spec it say:

"If an array is declared as the last member of a shader storage block
and the size is not specified at compile-time, it is sized at run-time.
In all other cases, arrays are sized only at compile-time."

Reviewed-by: Samuel Iglesias Gonsálvez <siglesias@igalia.com>