Prepare for developing Halo 2.9.0 (#4344)

#### What type of PR is this?

/kind cleanup
/area core

#### What this PR does / why we need it:

Bump up Halo to `2.9.0-SNAPSHOT` for developing Halo 2.9.0.

#### Does this PR introduce a user-facing change?

```release-note
None
```

README.md

@@ -30,7 +30,7 @@ docker run \
   --name halo \
   -p 8090:8090 \
   -v ~/.halo2:/root/.halo2 \
-  halohub/halo:2.7 \
+  halohub/halo:2.8 \
   --halo.security.initializer.superadminusername=admin \
   --halo.security.initializer.superadminpassword=P@88w0rd
 ```
@@ -46,7 +46,7 @@ docker run \
 
 ## 生态
 
-可访问 [awesome-halo](https://github.com/halo-sigs/awesome-halo) 查看已经适用于 Halo 2.0 的主题和插件，以及适用于 Halo
+可访问 [awesome-halo](https://github.com/halo-sigs/awesome-halo) 查看已经适用于 Halo 2.x 的主题和插件，以及适用于 Halo
 1.x 的相关仓库。
 
 ## 许可证

console/package.json

@@ -1,6 +1,6 @@
 {
   "name": "@halo-dev/console",
-  "version": "2.8.0",
+  "version": "2.9.0",
   "scripts": {
     "prepare": "cd .. && husky install console/.husky",
     "dev": "vite --host",

console/packages/api-client/package.json

@@ -1,6 +1,6 @@
 {
   "name": "@halo-dev/api-client",
-  "version": "2.8.0",
+  "version": "2.9.0",
   "description": "",
   "scripts": {
     "build": "unbuild",

console/packages/components/package.json

@@ -1,6 +1,6 @@
 {
   "name": "@halo-dev/components",
-  "version": "1.7.0",
+  "version": "1.8.0",
   "description": "",
   "files": [
     "dist"

console/packages/shared/package.json

@@ -1,6 +1,6 @@
 {
   "name": "@halo-dev/console-shared",
-  "version": "2.8.0",
+  "version": "2.9.0",
   "description": "",
   "files": [
     "dist"

gradle.properties

@@ -1 +1 @@
-version=2.8.0-SNAPSHOT
+version=2.9.0-SNAPSHOT