Revert "[Static Web Assets] Allow assets with empty base paths (#17414)"

This reverts commit b4d2f9a.

Author: dougbu

src/Hosting/Hosting/src/StaticWebAssets/StaticWebAssetsFileProvider.cs

@@ -46,11 +46,6 @@ public IDirectoryContents GetDirectoryContents(string subpath)
         {
             var modifiedSub = NormalizePath(subpath);
 
-            if (BasePath == "/")
-            {
-                return InnerProvider.GetDirectoryContents(modifiedSub);
-            }
-
             if (StartsWithBasePath(modifiedSub, out var physicalPath))
             {
                 return InnerProvider.GetDirectoryContents(physicalPath.Value);
@@ -72,11 +67,6 @@ public IFileInfo GetFileInfo(string subpath)
         {
             var modifiedSub = NormalizePath(subpath);
 
-            if (BasePath == "/")
-            {
-                return InnerProvider.GetFileInfo(subpath);
-            }
-
             if (!StartsWithBasePath(modifiedSub, out var physicalPath))
             {
                 return new NotFoundFileInfo(subpath);

src/Hosting/Hosting/test/StaticWebAssets/StaticWebAssetsFileProviderTests.cs

@@ -117,35 +117,6 @@ public void StaticWebAssetsFileProvider_FindsFileWithSpaces()
             Assert.True(provider.GetFileInfo("/_content/Static Web Assets.txt").Exists);
         }
 
-        [Fact]
-        public void GetDirectoryContents_HandlesEmptyBasePath()
-        {
-            // Arrange
-            var provider = new StaticWebAssetsFileProvider("/",
-                Path.Combine(AppContext.BaseDirectory, "testroot", "wwwroot"));
-
-            // Act
-            var directory = provider.GetDirectoryContents("/Static Web/");
-
-            // Assert
-            Assert.Collection(directory,
-                file =>
-                {
-                    Assert.Equal("Static Web.txt", file.Name);
-                });
-        }
-
-        [Fact]
-        public void StaticWebAssetsFileProviderWithEmptyBasePath_FindsFile()
-        {
-            // Arrange & Act
-            var provider = new StaticWebAssetsFileProvider("/",
-                Path.Combine(AppContext.BaseDirectory, "testroot", "wwwroot"));
-
-            // Assert
-            Assert.True(provider.GetFileInfo("/Static Web Assets.txt").Exists);
-        }
-
         [Fact]
         public void GetFileInfo_DoesNotMatch_IncompletePrefixSegments()
         {