Bump postcss from 8.2.2 to 8.2.6

Bumps [postcss](https://github.com/postcss/postcss) from 8.2.2 to 8.2.6.
- [Release notes](https://github.com/postcss/postcss/releases)
- [Changelog](https://github.com/postcss/postcss/blob/main/CHANGELOG.md)
- [Commits](https://github.com/postcss/postcss/compare/8.2.2...8.2.6)

Signed-off-by: dependabot[bot] <support@github.com>

package-lock.json

@@ -7949,9 +7949,9 @@
       "dev": true
     },
     "postcss": {
-      "version": "8.2.2",
-      "resolved": "https://registry.npmjs.org/postcss/-/postcss-8.2.2.tgz",
-      "integrity": "sha512-HM1NDNWLgglJPQQMNwvLxgH2KcrKZklKLi/xXYIOaqQB57p/pDWEJNS83PVICYsn1Dg/9C26TiejNr422/ePaQ==",
+      "version": "8.2.6",
+      "resolved": "https://registry.npmjs.org/postcss/-/postcss-8.2.6.tgz",
+      "integrity": "sha512-xpB8qYxgPuly166AGlpRjUdEYtmOWx2iCwGmrv4vqZL9YPVviDVPZPRXxnXr6xPZOdxQ9lp3ZBFCRgWJ7LE3Sg==",
       "dev": true,
       "requires": {
         "colorette": "^1.2.1",

package.json

@@ -31,7 +31,7 @@
     "@types/react-calendar": "^3.1.2",
     "@types/uuid": "^8.3.0",
     "jest": "^26.6.3",
-    "postcss": "^8.2.2",
+    "postcss": "^8.2.6",
     "postcss-flexbugs-fixes": "^5.0.2",
     "postcss-preset-env": "^6.7.0",
     "swr": "^0.4.2",