feat: Official support for React18 incl StrictMode (#1875)

* chore: update some deps

react & testing

* fix: cleanup observers in layout cleanup

* chore: update peerdeps

* chore: add changesets

* fix: useTransition on initial mount

should run usedTransitions when the component is mounted

* chore: bump @types packages and fix TS errors

* fix: generic In and Out are reserved words in ts 4.7

resolves #1883

* refactor: use better(?) plugin for snapshots

* fix: docs site

* chore: tidy ups

Author: joshuaellis

.changeset/orange-rivers-applaud.md

@@ -0,0 +1,21 @@
+{
+  "mode": "pre",
+  "tag": "beta",
+  "initialVersions": {
+    "@react-spring/demo": "1.0.0",
+    "@react-spring/docs": "1.0.6",
+    "@react-spring/animated": "9.4.4",
+    "@react-spring/core": "9.4.4",
+    "@react-spring/parallax": "9.4.4",
+    "@react-spring/rafz": "9.4.4",
+    "react-spring": "9.4.4",
+    "@react-spring/shared": "9.4.4",
+    "@react-spring/types": "9.4.4",
+    "@react-spring/konva": "9.4.4",
+    "@react-spring/native": "9.4.4",
+    "@react-spring/three": "9.4.4",
+    "@react-spring/web": "9.4.4",
+    "@react-spring/zdog": "9.4.4"
+  },
+  "changesets": []
+}