Fix compression-webpack-plugin configuration (#16356)
Fix compression-webpack-plugin configuration (#16356)

compression-webpack-plugin 6.0.0 has changed how filenames were generated,
so from #14892 onward (Mastodon v3.3.0 and later), compressed files were
output to a file named `.gz` instead of the correct filenames.
MitarashiDango/mastodon,tootsuite/mastodon,pinfort/mastodon,im-in-space/mastodon,tootcafe/mastodon,cobodo/mastodon,cobodo/mastodon,musashino205/mastodon,h3zjp/mastodon,maa123/mastodon,glitch-soc/mastodon,glitch-soc/mastodon,lindwurm/mastodon,Kirishima21/mastodon,abcang/mastodon,ikuradon/mastodon,gol-cha/mastodon,maa123/mastodon,masto-donte-com-br/mastodon,masto-donte-com-br/mastodon,gol-cha/mastodon,im-in-space/mastodon,Ryanaka/mastodon,MitarashiDango/mastodon,MitarashiDango/mastodon,gol-cha/mastodon,abcang/mastodon,im-in-space/mastodon,yi0713/mastodon,cobodo/mastodon,koba-lab/mastodon,tootsuite/mastodon,musashino205/mastodon,yukimochi/mastodon,h3zjp/mastodon,yi0713/mastodon,ikuradon/mastodon,gol-cha/mastodon,abcang/mastodon,masto-donte-com-br/mastodon,glitch-soc/mastodon,masto-donte-com-br/mastodon,imas/mastodon,Ryanaka/mastodon,koba-lab/mastodon,lindwurm/mastodon,Kirishima21/mastodon,tootcafe/mastodon,Kirishima21/mastodon,h3zjp/mastodon,im-in-space/mastodon,glitch-soc/mastodon,theoria24/mastodon,tootcafe/mastodon,h3zjp/mastodon,tootsuite/mastodon,yukimochi/mastodon,yukimochi/mastodon,theoria24/mastodon,yukimochi/mastodon,imas/mastodon,ykzts/mastodon,imas/mastodon,pinfort/mastodon,pinfort/mastodon,ykzts/mastodon,tootcafe/mastodon,theoria24/mastodon,abcang/mastodon,lindwurm/mastodon,ikuradon/mastodon,imas/mastodon,Ryanaka/mastodon,MitarashiDango/mastodon,lindwurm/mastodon,Kirishima21/mastodon,theoria24/mastodon,yi0713/mastodon,ykzts/mastodon,koba-lab/mastodon,musashino205/mastodon,musashino205/mastodon,cobodo/mastodon,tootsuite/mastodon,ykzts/mastodon,maa123/mastodon,Ryanaka/mastodon,yi0713/mastodon,ikuradon/mastodon,pinfort/mastodon,koba-lab/mastodon,maa123/mastodon