message: Upgrade VK Sans plugin to postcss 8
diff: /* stylelint-disable */
  -const postcss = require("postcss");
  const fs = require("fs");
  const path = require("path");
  @@ -88,14 +87,18 @@ const updateFontSizeStats = (value = "", platform) => {
  return ++cache.fontSizeUsages[value];
  };
  -const extendConfigWithCustomProperties = (customPropertiesFile, platform) => {
  +const extendConfigWithCustomProperties = (
  + customPropertiesFile,
  + platform,
  + parse
  +) => {
  const customProperties = fs.readFileSync(
  path.resolve(customPropertiesFile),
  "utf8"
  );
  const customPropertiesValues = {};
  - postcss.parse(customProperties).walkRules((rule) => {
  + parse(customProperties).walkRules((rule) => {
  if (
  rule.parent.type === "root" &&
  rule.type === "rule" &&
  @@ -153,18 +156,20 @@ const initializeConfig = (platform, overrides) => {
  }
  };
  -const initializeCustomPropertiesFiles = (customPropertiesFiles, platform) => {
  +const initializeCustomPropertiesFiles = (
  + customPropertiesFiles,
  + platform,
  + parse
  +) => {
  customPropertiesFiles.forEach((i) => {
  if (!initializedCustomPropertiesFiles.has(i)) {
  - extendConfigWithCustomProperties(i, platform);
  + extendConfigWithCustomProperties(i, platform, parse);
  initializedCustomPropertiesFiles.add(i);
  }
  });
  };
  -const VkSansMandatoryDeclarations = postcss.plugin(
  - "vk-sans-mandatory-declarations",
  - (opts) => {
  +module.exports = (opts) => {
  const {
  debug,
  overrides,
  @@ -178,13 +183,15 @@ const VkSansMandatoryDeclarations = postcss.plugin(
  varName = "--palette-vk-font",
  } = opts;
  - return (css) => {
  + return {
  + postcssPlugin: "vk-sans-mandatory-declarations",
  + Once(css, { parse }) {
  if (!cache.config[platform]) {
  initializeConfig(platform, overrides);
  }
  if (customPropertiesFiles) {
  - initializeCustomPropertiesFiles(customPropertiesFiles, platform);
  + initializeCustomPropertiesFiles(customPropertiesFiles, platform, parse);
  }
  if (
  @@ -336,8 +343,8 @@ const VkSansMandatoryDeclarations = postcss.plugin(
  }
  });
  }
  + },
  + };
  };
  - }
  -);
  -module.exports = VkSansMandatoryDeclarations;
  +module.exports.postcss = true;
  