[C#] Drop "build" file extension assignment

[deathaxe]

Fixes #1862

This commit unassignes build file extension from NAnt Build File syntax as it is a too generic extension used by many syntaxes.

With this change *.build files need to be assigned to NAnt Build File manually if desired.

[FichteFoll]

I assume there isn't a first_line_match rule we could add here instead to attempt to resolve ambiguities with this extension?

[michaelblyons]

Looks like build files are XML, so the first line says "Hey I'm XML" rather than something helpful. See sample from official doc, unescaped below.

<?xml version="1.0"?>
    <project name="Hello World" default="build" basedir=".">
        <description>The Hello World of build files.</description>
        <property name="debug" value="true" overwrite="false" />
        <target name="clean" description="remove all generated files">
            <delete file="HelloWorld.exe" failonerror="false" />
            <delete file="HelloWorld.pdb" failonerror="false" />
        </target>
        <target name="build" description="compiles the source code">
            <csc target="exe" output="HelloWorld.exe" debug="${debug}">
                <sources>
                    <includes name="HelloWorld.cs" />
                </sources>
            </csc>
        </target>
    </project>

[FichteFoll]

Well, that's unfortuantely not enough to distinguish a "NAnt Build File" from any other xml file.

[deathaxe]

TBH, I don't know why a NAnt syntax exists at all. It is just a very naive and basic XML syntax which doesn't add any value compared to using XML.sublime-syntax.

[michaelblyons]

TBH, I don't know why a NAnt syntax exists at all. It is just a very naive and basic XML syntax which doesn't add any value compared to using XML.sublime-syntax.

Took a look. He's not wrong. IMO delete it.

If someone really wants to, they can extend XML and highlight specific properties.