fix: npm run start with existing build artifacts (#3100)

Exclude build outputs (.js, .d.ts, .js.map) from the esbuild tsconfig
so TypeScript doesn't try to overwrite them.

Closes #2712

Assisted-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: bennypowers

.changeset/fix-start-build-artifacts.md

@@ -0,0 +1,6 @@
+---
+"@patternfly/elements": patch
+---
+
+`npm run start` no longer fails when TypeScript build artifacts
+are present in the working tree.

tsconfig.esbuild.json

@@ -9,7 +9,16 @@
     "**/demo/*.d.ts",
     "**/_temp/**/*",
     "**/*.story.*",
-    "**/test/*_e2e*"
+    "**/test/*_e2e*",
+    "elements/**/*.js",
+    "elements/**/*.d.ts",
+    "elements/**/*.js.map",
+    "core/**/*.js",
+    "core/**/*.d.ts",
+    "core/**/*.js.map",
+    "tools/**/*.js",
+    "tools/**/*.d.ts",
+    "tools/**/*.js.map"
   ],
   "compilerOptions": {
     "allowJs": true,