I updated the packages and after starting npm i got 2 warning which are follows:
WARNING in ./src/assets/scss/style.scss (./node_modules/@angular-devkit/build-angular/src/angular-cli-files/plugins/raw-css-loader.js!./node_modules/postcss-loader/src??embedded!./node_modules/sass-loader/lib/loader.js??ref--13-3!./src/assets/scss/style.scss) Module Warning (from ./node_modules/postcss-loader/src/index.js): Warning
(5013:3) end value has mixed support, consider using flex-end instead
WARNING in ./src/assets/scss/style.scss (./node_modules/@angular-devkit/build-angular/src/angular-cli-files/plugins/raw-css-loader.js!./node_modules/postcss-loader/src??embedded!./node_modules/sass-loader/lib/loader.js??ref--13-3!./src/assets/scss/style.scss) Module Warning (from ./node_modules/postcss-loader/src/index.js): Warning
(5019:3) end value has mixed support, consider using flex-end instead