This patch fixes T96655, bloom crashing Eevee.

The error occurs because rB472fc0c55848b2e2d428cfb4f7debb80a4e12081 added vec3 safe_color(vec3 c) to common_math_lib.glsl.

However, vec3 safe_color(vec3 c) already exists in effect_bloom_frag.glsl.
This means vec3 safe_color(vec3 c) is duplicated within common_math_lib.glsl and effect_bloom_frag.glsl.

The duplicate code in effect_bloom_frag.glsl can be removed since it's no longer needed.

(I checked the remaining methods, there shouldn't be any additional duplicate code)