Theme build instruction doesn't work anymore

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• I have read the contributing guide lines at https://github.com/opnsense/docs/blob/master/CONTRIBUTING.md
• I have searched the existing issues and I am convinced that mine is new.

Describe the issue

When building using the command below, some deprecation warnings and an error seem to show up.

sass -I bower_components/wyrm/sass/ -I bower_components/bourbon/dist/ -I bower_components/neat/app/assets/stylesheets/ -I bower_components/font-awesome/scss/ themes/opnsense/sass/theme.sass  > source/_static/css/opnsense.css

DEPRECATION WARNING on line 81, column 5 of bower_components/bourbon/dist/css3/_flex-box.scss: 
@elseif is deprecated and will not be supported in future Sass versions.
Use "@else if" instead.
   ╷
81 │     @elseif $value == "inline-flex" {
   │     ^^^^^^^
   ╵

DEPRECATION WARNING on line 127, column 5 of bower_components/bourbon/dist/css3/_flex-box.scss: 
@elseif is deprecated and will not be supported in future Sass versions.
Use "@else if" instead.
    ╷
127 │     @elseif $value == "row-reverse" {
    │     ^^^^^^^
    ╵

DEPRECATION WARNING on line 132, column 5 of bower_components/bourbon/dist/css3/_flex-box.scss: 
@elseif is deprecated and will not be supported in future Sass versions.
Use "@else if" instead.
    ╷
132 │     @elseif $value == column {
    │     ^^^^^^^
    ╵

DEPRECATION WARNING on line 136, column 5 of bower_components/bourbon/dist/css3/_flex-box.scss: 
@elseif is deprecated and will not be supported in future Sass versions.
Use "@else if" instead.
    ╷
136 │     @elseif $value == "column-reverse" {
    │     ^^^^^^^
    ╵

DEPRECATION WARNING on line 165, column 5 of bower_components/bourbon/dist/css3/_flex-box.scss: 
@elseif is deprecated and will not be supported in future Sass versions.
Use "@else if" instead.
    ╷
165 │     @elseif $value == wrap {
    │     ^^^^^^^
    ╵

DEPRECATION WARNING on line 169, column 5 of bower_components/bourbon/dist/css3/_flex-box.scss: 
@elseif is deprecated and will not be supported in future Sass versions.
Use "@else if" instead.
    ╷
169 │     @elseif $value == "wrap-reverse" {
    │     ^^^^^^^
    ╵

DEPRECATION WARNING on line 227, column 5 of bower_components/bourbon/dist/css3/_flex-box.scss: 
@elseif is deprecated and will not be supported in future Sass versions.
Use "@else if" instead.
    ╷
227 │     @elseif $value == "flex-end" {
    │     ^^^^^^^
    ╵

DEPRECATION WARNING on line 231, column 5 of bower_components/bourbon/dist/css3/_flex-box.scss: 
@elseif is deprecated and will not be supported in future Sass versions.
Use "@else if" instead.
    ╷
231 │     @elseif $value == "space-between" {
    │     ^^^^^^^
    ╵

DEPRECATION WARNING on line 235, column 5 of bower_components/bourbon/dist/css3/_flex-box.scss: 
@elseif is deprecated and will not be supported in future Sass versions.
Use "@else if" instead.
    ╷
235 │     @elseif $value == "space-around" {
    │     ^^^^^^^
    ╵

DEPRECATION WARNING on line 260, column 5 of bower_components/bourbon/dist/css3/_flex-box.scss: 
@elseif is deprecated and will not be supported in future Sass versions.
Use "@else if" instead.
    ╷
260 │     @elseif $value == "flex-end" {
    │     ^^^^^^^
    ╵

DEPRECATION WARNING on line 283, column 5 of bower_components/bourbon/dist/css3/_flex-box.scss: 
@elseif is deprecated and will not be supported in future Sass versions.
Use "@else if" instead.
    ╷
283 │     @elseif $value == "flex-end" {
    │     ^^^^^^^
    ╵

DEPRECATION WARNING on line 303, column 5 of bower_components/bourbon/dist/css3/_flex-box.scss: 
@elseif is deprecated and will not be supported in future Sass versions.
Use "@else if" instead.
    ╷
303 │     @elseif $value == "flex-end" {
    │     ^^^^^^^
    ╵

DEPRECATION WARNING on line 307, column 5 of bower_components/bourbon/dist/css3/_flex-box.scss: 
@elseif is deprecated and will not be supported in future Sass versions.
Use "@else if" instead.
    ╷
307 │     @elseif $value == "space-between" {
    │     ^^^^^^^
    ╵

DEPRECATION WARNING on line 311, column 5 of bower_components/bourbon/dist/css3/_flex-box.scss: 
@elseif is deprecated and will not be supported in future Sass versions.
Use "@else if" instead.
    ╷
311 │     @elseif $value == "space-around" {
    │     ^^^^^^^
    ╵

Error: expected newline.
    ╷
246 │     border-color: $input-focus-color
    │                 ^
    ╵
  wyrm_core/_form.sass 246:17           @import
  themes/opnsense/sass/theme.sass 38:9  root stylesheet