[ImgBot] Optimize images

*Total -- 14,958.50kb -> 14,668.31kb (1.94%)

/public/textures/Fire_diffuse.png -- 234.16kb -> 170.49kb (27.19%)
/public/textures/Fire_emissive.jpeg -- 467.57kb -> 444.53kb (4.93%)
/public/textures/Robot_normal.jpeg -- 3,654.02kb -> 3,531.76kb (3.35%)
/public/textures/Robot_diffuse.jpeg -- 3,568.51kb -> 3,495.05kb (2.06%)
/public/textures/Robot_specularGlossiness.png -- 7,034.25kb -> 7,026.47kb (0.11%)

Signed-off-by: ImgBotApp <ImgBotHelp@gmail.com>

Author: ImgBotApp