re-land "update the repo references for package:file (#55906)" (#55935)

This is a re-land of the reverted PR, #55916 (it depended
on a dart roll that was reverted, and has subsequently been re-landed).

From the original PR:

> The SoT repository for `package:file` has changed from
google/file.dart to dart-lang/tools; this PR updates the DEPS file and
the hard-coded paths in the two pubspec.yaml files (see
dart-lang/tools#674).

Author: devoncarew

DEPS

@@ -171,7 +171,6 @@ vars = {
   "upstream_dartdoc": "https://github.com/dart-lang/dartdoc.git",
   "upstream_equatable": "https://github.com/felangel/equatable.git",
   "upstream_ffi": "https://github.com/dart-lang/ffi.git",
-  "upstream_file": "https://github.com/google/file.dart.git",
   "upstream_fixnum": "https://github.com/dart-lang/fixnum.git",
   "upstream_flatbuffers": "https://github.com/google/flatbuffers.git",
   "upstream_freetype2": "https://gitlab.freedesktop.org/freetype/freetype.git",
@@ -391,9 +390,6 @@ deps = {
   'src/flutter/third_party/dart/third_party/pkg/dartdoc':
    Var('dart_git') + '/dartdoc.git@80c6f18f34b387d4b9ce89ddd2e3049093335f9d',
 
-  'src/flutter/third_party/dart/third_party/pkg/file':
-   Var('dart_git') + '/external/github.com/google/file.dart@6842feaef1c4e06239bd30f8d3ef722838b1c97e',
-
   'src/flutter/third_party/dart/third_party/pkg/fixnum':
    Var('dart_git') + '/fixnum.git@83293b8ed86ccd574a94fcf4a2da43f31c1b43e0',
 

pubspec.yaml

@@ -194,7 +194,7 @@ dependency_overrides:
   expect:
     path: ./third_party/dart/pkg/expect
   file:
-    path: ./third_party/dart/third_party/pkg/file/packages/file
+    path: ./third_party/dart/third_party/pkg/tools/pkgs/file
   ffi:
     path: ./third_party/dart/third_party/pkg/native/pkgs/ffi
   fixnum:

web_sdk/pubspec.yaml

@@ -33,7 +33,7 @@ dependency_overrides: # Must include all transitive dependencies from the "any"
   dart_internal:
     path: ../third_party/dart/pkg/dart_internal
   file:
-    path: ../third_party/dart/third_party/pkg/file/packages/file
+    path: ../third_party/dart/third_party/pkg/tools/pkgs/file
   glob:
     path: ../third_party/dart/third_party/pkg/glob
   macros: