build: Replace 'grunt-svgmin' with npm based 'svgo'

Replacing 'grunt-svgmin' with 'svgo' v2.8.0.
Also
- replacing Grunt based task with npm equivalent including excluded
  SVG file.
- changing to JS based '.svgo.config.js'

Bug: [T246321](https://phabricator.wikimedia.org/T246321)
Bug: [T278656](https://phabricator.wikimedia.org/T278656)

.svgo.config.js

@@ -0,0 +1,40 @@
+/**
+ * SVGO Configuration
+ * Compatible to v2.4.0+
+ * Recommended options from:
+ * https://www.mediawiki.org/wiki/Manual:Coding_conventions/SVG#Exemplified_safe_configuration
+ */
+module.exports = {
+	plugins: [
+		{
+			// Set of built-in plugins enabled by default.
+			name: 'preset-default',
+			params: {
+				overrides: {
+					cleanupIDs: false,
+					removeDesc: false,
+					removeTitle: false,
+					removeViewBox: false,
+					// If the SVG doesn't start with an XML declaration, then its MIME type will
+					// be detected as "text/plain" rather than "image/svg+xml" by libmagic and,
+					// consequently, MediaWiki's CSSMin CSS minifier. libmagic's default database
+					// currently requires that SVGs contain an XML declaration:
+					// https://github.com/threatstack/libmagic/blob/master/magic/Magdir/sgml#L5
+					removeXMLProcInst: false
+				}
+			}
+		},
+		'removeRasterImages',
+		'sortAttrs'
+	],
+	// Set whitespace according to Wikimedia Coding Conventions.
+	// @see https://github.com/svg/svgo/blob/main/lib/svgo/coa.js#L194 for more config options
+	js2svg: {
+		eol: 'lf',
+		finalNewline: true,
+		// Configure the indent to tabs (default 4 spaces) used by `--pretty` here.
+		indent: '\t',
+		pretty: true
+	},
+	multipass: true
+}

Gruntfile.js

@@ -28,7 +28,6 @@ module.exports = function ( grunt ) {
 	grunt.loadNpmTasks( '@lodder/grunt-postcss' );
 	grunt.loadNpmTasks( 'grunt-replace' );
 	grunt.loadNpmTasks( 'grunt-stylelint' );
-	grunt.loadNpmTasks( 'grunt-svgmin' );
 
 	grunt.initConfig( {
 		// Build – JavaScript
@@ -108,43 +107,6 @@ module.exports = function ( grunt ) {
 			}
 		},
 
-		svgmin: {
-			options: {
-				js2svg: {
-					indent: '\t',
-					multipass: true,
-					pretty: true
-				},
-				plugins: [ {
-					cleanupIDs: false
-				}, {
-					removeDesc: true
-				}, {
-					removeRasterImages: true
-				}, {
-					removeTitle: false
-				}, {
-					removeViewBox: false
-				}, {
-					removeXMLProcInst: false
-				}, {
-					sortAttrs: true
-				} ]
-			},
-			all: {
-				files: [ {
-					expand: true,
-					cwd: './',
-					src: [
-						'**/*.svg',
-						'!img/visual-style/principles-paper-ink.svg'
-					],
-					dest: './',
-					ext: '.svg'
-				} ]
-			}
-		},
-
 		replace: {
 			dist: {
 				options: {
@@ -183,7 +145,6 @@ module.exports = function ( grunt ) {
 	} );
 
 	grunt.registerTask( 'lint', [ 'eslint', 'stylelint' ] );
-	grunt.registerTask( 'images', [ 'svgmin' ] );
 	grunt.registerTask( 'images-pre-production', [ 'replace' ] );
 	grunt.registerTask( 'default', [ 'concat', 'uglify', 'postcss:dev', 'postcss:min' ] );
 };