Fix invalid csharp_space_around_declaration_statements option value

[xtqqczze]

The only valid option values are ignore and false.

https://learn.microsoft.com/dotnet/fundamentals/code-analysis/style-rules/csharp-formatting-options#csharp_space_around_declaration_statements

roslyn/src/Workspaces/SharedUtilitiesAndExtensions/Compiler/CSharp/Formatting/CSharpFormattingOptions2.cs

Lines 118 to 123 in e628ec6

	public static Option2<bool> SpacesIgnoreAroundVariableDeclaration { get; } = CreateOption(
	CSharpFormattingOptionGroups.Spacing, "csharp_space_around_declaration_statements",
	CSharpSyntaxFormattingOptions.SpacingDefault.HasFlag(SpacePlacement.IgnoreAroundVariableDeclaration),
	new EditorConfigValueSerializer<bool>(
	s => DetermineIfIgnoreSpacesAroundVariableDeclarationIsSet(s),
	v => v ? "ignore" : "false"))

[JoeRobich]

@xtqqczze Thanks!

[xtqqczze]

It should be noted that the invalid do_not_ignore option is widely used:

https://github.com/search?q=org%3Adotnet+%22csharp_space_around_declaration_statements+%3D+do_not_ignore%22+path%3A.editorconfig&type=code

It is also present in a test:

roslyn/src/Workspaces/CSharpTest/Formatting/EditorConfigOptionParserTests.cs

Lines 111 to 118 in e628ec6

	[Theory,
	InlineData("do_not_ignore"),
	InlineData(", "),
	InlineData(" ignor ")]
	public void TestDetermineIfIgnoreSpacesAroundVariableDeclarationIsSetFalse(string value)
	=> Assert.False(CSharpFormattingOptions2.DetermineIfIgnoreSpacesAroundVariableDeclarationIsSet(value),
	$"Expected option {value} to be un-set");
	}

[xtqqczze]

@agocke can you merge?

[xtqqczze]

Opened dotnet/performance#5132