Use default subpath condition for fallback

The intention of #35 was to have `import` be prioritized above all, and browsers/require to load UMD.

Author: jridgewell

packages/gen-mapping/package.json

@@ -21,11 +21,7 @@
           "types": "./types/gen-mapping.d.mts",
           "default": "./dist/gen-mapping.mjs"
         },
-        "require": {
-          "types": "./types/gen-mapping.d.cts",
-          "default": "./dist/gen-mapping.umd.js"
-        },
-        "browser": {
+        "default": {
           "types": "./types/gen-mapping.d.cts",
           "default": "./dist/gen-mapping.umd.js"
         }

packages/remapping/package.json

@@ -22,11 +22,7 @@
           "types": "./types/remapping.d.mts",
           "default": "./dist/remapping.mjs"
         },
-        "require": {
-          "types": "./types/remapping.d.cts",
-          "default": "./dist/remapping.umd.js"
-        },
-        "browser": {
+        "default": {
           "types": "./types/remapping.d.cts",
           "default": "./dist/remapping.umd.js"
         }

packages/source-map/package.json

@@ -22,11 +22,7 @@
           "types": "./types/source-map.d.mts",
           "default": "./dist/source-map.mjs"
         },
-        "require": {
-          "types": "./types/source-map.d.cts",
-          "default": "./dist/source-map.umd.js"
-        },
-        "browser": {
+        "default": {
           "types": "./types/source-map.d.cts",
           "default": "./dist/source-map.umd.js"
         }

packages/sourcemap-codec/package.json

@@ -21,11 +21,7 @@
           "types": "./types/sourcemap-codec.d.mts",
           "default": "./dist/sourcemap-codec.mjs"
         },
-        "require": {
-          "types": "./types/sourcemap-codec.d.cts",
-          "default": "./dist/sourcemap-codec.umd.js"
-        },
-        "browser": {
+        "default": {
           "types": "./types/sourcemap-codec.d.cts",
           "default": "./dist/sourcemap-codec.umd.js"
         }

packages/trace-mapping/package.json

@@ -21,11 +21,7 @@
           "types": "./types/trace-mapping.d.mts",
           "default": "./dist/trace-mapping.mjs"
         },
-        "require": {
-          "types": "./types/trace-mapping.d.cts",
-          "default": "./dist/trace-mapping.umd.js"
-        },
-        "browser": {
+        "default": {
           "types": "./types/trace-mapping.d.cts",
           "default": "./dist/trace-mapping.umd.js"
         }