chore: pin @types/prettier to 2.6.0 (#20322)

@types/prettier is a transitive dependency of `jest`. Version `2.6.1`
introduced a breaking change by increasing the minimum supported
version of typescript to `4.2`. See related issue for more information.

re #20319


----

### All Submissions:

* [ ] Have you followed the guidelines in our [Contributing guide?](https://github.com/aws/aws-cdk/blob/master/CONTRIBUTING.md)

### Adding new Unconventional Dependencies:

* [ ] This PR adds new unconventional dependencies following the process described [here](https://github.com/aws/aws-cdk/blob/master/CONTRIBUTING.md/#adding-new-unconventional-dependencies)

### New Features

* [ ] Have you added the new feature to an [integration test](https://github.com/aws/aws-cdk/blob/master/INTEGRATION_TESTS.md)?
	* [ ] Did you use `yarn integ` to deploy the infrastructure and generate the snapshot (i.e. `yarn integ` without `--dry-run`)?

*By submitting this pull request, I confirm that my contribution is made under the terms of the Apache-2.0 license*

Author: corymhall

package.json

@@ -16,6 +16,7 @@
     "postinstall": "patch-package --error-on-fail"
   },
   "devDependencies": {
+    "@types/prettier": "2.6.0",
     "@yarnpkg/lockfile": "^1.1.0",
     "cdk-generate-synthetic-examples": "^0.1.10",
     "conventional-changelog-cli": "^2.2.2",

packages/aws-cdk/lib/init-templates/v1/app/typescript/package.json

@@ -12,6 +12,7 @@
   },
   "devDependencies": {
     "@aws-cdk/assertions": "%cdk-version%",
+    "@types/prettier": "2.6.0",
     "@types/jest": "^27.5.0",
     "@types/node": "10.17.27",
     "jest": "^27.5.1",

packages/aws-cdk/lib/init-templates/v1/lib/typescript/package.json

@@ -11,6 +11,7 @@
   "devDependencies": {
     "@aws-cdk/assertions": "%cdk-version%",
     "@types/jest": "^27.5.0",
+    "@types/prettier": "2.6.0",
     "@types/node": "10.17.27",
     "jest": "^27.5.1",
     "ts-jest": "^27.1.4",

packages/aws-cdk/lib/init-templates/v1/sample-app/typescript/package.json

@@ -15,6 +15,7 @@
     "@aws-cdk/assertions": "%cdk-version%",
     "@types/jest": "^27.5.0",
     "@types/node": "10.17.27",
+    "@types/prettier": "2.6.0",
     "jest": "^27.5.1",
     "ts-jest": "^27.1.4",
     "ts-node": "^10.7.0",

packages/aws-cdk/lib/init-templates/v2/app/typescript/package.json

@@ -13,6 +13,7 @@
   "devDependencies": {
     "@types/jest": "^27.5.0",
     "@types/node": "10.17.27",
+    "@types/prettier": "2.6.0",
     "jest": "^27.5.1",
     "ts-jest": "^27.1.4",
     "aws-cdk": "%cdk-version%",

packages/aws-cdk/lib/init-templates/v2/lib/typescript/package.json

@@ -11,6 +11,7 @@
   "devDependencies": {
     "@types/jest": "^27.5.0",
     "@types/node": "10.17.27",
+    "@types/prettier": "2.6.0",
     "aws-cdk-lib": "%cdk-version%",
     "constructs": "%constructs-version%",
     "jest": "^27.5.1",

packages/aws-cdk/lib/init-templates/v2/sample-app/typescript/package.json

@@ -14,6 +14,7 @@
     "aws-cdk": "%cdk-version%",
     "@types/jest": "^27.5.0",
     "@types/node": "10.17.27",
+    "@types/prettier": "2.6.0",
     "jest": "^27.5.1",
     "ts-jest": "^27.1.4",
     "ts-node": "^10.7.0",

yarn.lock

@@ -1957,7 +1957,7 @@
   resolved "https://registry.npmjs.org/@types/parse-json/-/parse-json-4.0.0.tgz#2f8bb441434d163b35fb8ffdccd7138927ffb8c0"
   integrity sha512-//oorEZjL6sbPcKUaCdIGlIUeH26mgzimjBB77G6XRgnDl/L5wOnpyBGRe/Mmf5CVW3PwEBE1NjiMZ/ssFh4wA==
 
-"@types/prettier@^2.1.5":
+"@types/prettier@2.6.0", "@types/prettier@^2.1.5":
   version "2.6.0"
   resolved "https://registry.npmjs.org/@types/prettier/-/prettier-2.6.0.tgz#efcbd41937f9ae7434c714ab698604822d890759"
   integrity sha512-G/AdOadiZhnJp0jXCaBQU449W2h716OW/EoXeYkCytxKL06X1WCXB4DZpp8TpZ8eyIJVS1cw4lrlkkSYU21cDw==