fix: support floating_modifier none; revert broken highlighting

 - fix floating_modifier $mod normal|inverse was being hightlighted as error
   reverting the floating_modifier change from dd83b63
 - will currently allow invalid syntax after floating_modifier

Co-authored-by: JosefLitos <litosjos@fit.cvut.cz>

runtime/syntax/i3config.vim

@@ -67,7 +67,7 @@ syn keyword i3ConfigBindKeyword bindsym bindcode contained skipwhite nextgroup=i
 syn region i3ConfigModeBlock matchgroup=i3ConfigKeyword start=/mode\ze\( --pango_markup\)\? \([^'" {]\+\|'[^']\+'\|".\+"\)\s\+{$/ end=/^}\zs$/ contained contains=i3ConfigShParam,@i3ConfigStrVar,i3ConfigBindKeyword,i3ConfigComment,i3ConfigParen fold keepend extend
 
 " 4.7 Floating modifier
-syn keyword i3ConfigKeyword floating_modifier contained skipwhite nextgroup=i3ConfigVariable,i3ConfigBindModkey
+syn match i3ConfigKeyword /^floating_modifier [$0-9A-Za-z]*$/ contains=i3ConfigVariable,i3ConfigBindModkey
 
 " 4.8 Floating window size
 syn keyword i3ConfigSizeSpecial x contained

runtime/syntax/swayconfig.vim

@@ -38,8 +38,8 @@ syn region swayConfigBlockOrphan start=/^\s\+\(--[a-z-]\+ \)*\([A-Z$][$a-zA-Z0-9
 
 syn region i3ConfigExec start=/ {$/ end=/^\s*}$/ contained contains=i3ConfigExecAction,@i3ConfigSh,i3ConfigComment fold keepend extend
 
-syn keyword swayConfigFloatingModifierOpts normal inverse contained
-syn match i3ConfigKeyword /floating_modifier [$a-zA-Z0-9+]\+ \(normal\|inverse\)$/ contained contains=i3ConfigVariable,i3ConfigBindModkey,swayConfigFloatingModifierOpts
+syn keyword swayConfigFloatingModifierOpts normal inverse none contained
+syn match i3ConfigKeyword /floating_modifier \(none\|[$a-zA-Z0-9+]\+ \(normal\|inverse\)\)$/ contained contains=i3ConfigVariable,i3ConfigBindModkey,swayConfigFloatingModifierOpts
 
 syn match swayConfigI3Param /--i3/ contains=i3ConfigShParam skipwhite nextgroup=i3ConfigEdgeOpts
 syn keyword i3ConfigKeyword hide_edge_borders contained skipwhite nextgroup=swayConfigI3Param,i3ConfigEdgeOpts