Use typescript for webpack config (#32507)

* Move declaration.d.ts to @types

Signed-off-by: Michael Telatynski <7t3chguy@gmail.com>

* Load customisations.json without `require`

Signed-off-by: Michael Telatynski <7t3chguy@gmail.com>

* Remove webpack rule from when we were consuming shared-components ts vs js

Signed-off-by: Michael Telatynski <7t3chguy@gmail.com>

* Avoid hardcoding paths to modules in webpack config

Signed-off-by: Michael Telatynski <7t3chguy@gmail.com>

* Convert webpack config to typescript

Signed-off-by: Michael Telatynski <7t3chguy@gmail.com>

* Stub js webpack/postcss plugins

Signed-off-by: Michael Telatynski <7t3chguy@gmail.com>

* Patch broken rollup types until https://github.com/getsentry/sentry-javascript-bundler-plugins/pull/870 is released

Signed-off-by: Michael Telatynski <7t3chguy@gmail.com>

* Install @types/postcss-import

Signed-off-by: Michael Telatynski <7t3chguy@gmail.com>

* Fix fdir relying on @types/picomatch

Signed-off-by: Michael Telatynski <7t3chguy@gmail.com>

* Update pnpm-lock.yaml

Signed-off-by: Michael Telatynski <7t3chguy@gmail.com>

---------

Signed-off-by: Michael Telatynski <7t3chguy@gmail.com>

tsconfig.json

@@ -6,7 +6,7 @@
         "resolveJsonModule": true,
         "esModuleInterop": true,
         "useDefineForClassFields": true,
-        "module": "es2022",
+        "module": "preserve",
         "moduleResolution": "bundler",
         "target": "es2022",
         "noUnusedLocals": true,
@@ -28,6 +28,7 @@
         "./test/**/*.ts",
         "./test/**/*.tsx",
         "./scripts/*.ts",
-        "./declaration.d.ts"
+        "./@types/*.d.ts",
+        "./webpack.config.ts"
     ]
 }