[ansible] Correct the formatting for linkmetadata minigraph generation for autonegotiation

[vdahiya12]

Description of PR

This PR refactors minigraph_link_meta.j2 by:

• Replacing link_metadata_defined with Jinja2 namespace (ns) for better variable scoping.
• Optimizing auto-negotiation detection using selectattr() to reduce looping.
• Improving code readability with structured formatting and consistent indentation.
  These changes enhance efficiency and maintainability without altering functionality.

Summary:
Fixes # (issue)

Type of change

• Bug fix
• Testbed and Framework(new/improvement)
• New Test case
  • Skipped for non-supported platforms
• Test case improvement

Back port request

• 202012
• 202205
• 202305
• 202311
• 202405
• 202411

Approach

What is the motivation for this PR?

Correct the minigraph generation For autoneg in SONiC

How did you do it?

How did you verify/test it?

This minigraph is generated

<LinkMetadataDeclaration>
    <Link xmlns:a="http://schemas.datacontract.org/2004/07/Microsoft.Search.Autopilot.Evolution">
                <a:LinkMetadata>
                    <a:Name i:nil="true"/>
                    <a:Properties>
                        <a:DeviceProperty>
                            <a:Name>AutoNegotiation</a:Name>
                            <a:Value>True</a:Value>
                        </a:DeviceProperty>
                        <a:DeviceProperty>
                            <a:Name>FECDisabled</a:Name>
                            <a:Reference i:nil="true"/>
                            <a:Value>True</a:Value>
                        </a:DeviceProperty>
                    </a:Properties>
                    <a:Key>fanout1:Ethernet39/1;sonic1:Ethernet7/1</a:Key>
                </a:LinkMetadata>
                <a:LinkMetadata>
                    <a:Name i:nil="true"/>
                    <a:Properties>
                        <a:DeviceProperty>
                            <a:Name>AutoNegotiation</a:Name>
                            <a:Value>True</a:Value>
                        </a:DeviceProperty>
                        <a:DeviceProperty>
                            <a:Name>FECDisabled</a:Name>
                            <a:Reference i:nil="true"/>
                            <a:Value>True</a:Value>
                        </a:DeviceProperty>
                    </a:Properties>
                    <a:Key>fanout1:Ethernet40/1;sonic1:Ethernet8/1</a:Key>
                </a:LinkMetadata>
                <a:LinkMetadata>
                    <a:Name i:nil="true"/>
                    <a:Properties>
                        <a:DeviceProperty>
                            <a:Name>AutoNegotiation</a:Name>
                            <a:Value>True</a:Value>
                        </a:DeviceProperty>
                        <a:DeviceProperty>
                            <a:Name>FECDisabled</a:Name>
                            <a:Reference i:nil="true"/>
                            <a:Value>True</a:Value>
                        </a:DeviceProperty>
                    </a:Properties>
                    <a:Key>fanout1:Ethernet41/1;sonic1:Ethernet9/1</a:Key>
                </a:LinkMetadata>
                <a:LinkMetadata>
                    <a:Name i:nil="true"/>
                    <a:Properties>
                        <a:DeviceProperty>
                            <a:Name>AutoNegotiation</a:Name>
                            <a:Value>True</a:Value>
                        </a:DeviceProperty>
                        <a:DeviceProperty>
                            <a:Name>FECDisabled</a:Name>
                            <a:Reference i:nil="true"/>
                            <a:Value>True</a:Value>
                        </a:DeviceProperty>
                    </a:Properties>
                    <a:Key>fanout1:Ethernet42/1;sonic1:Ethernet10/1</a:Key>
                </a:LinkMetadata>
  </Link>
</LinkMetadataDeclaration>

Any platform specific information?

Supported testbed topology if it's a new test case?

Documentation

[mssonicbld]

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[mssonicbld]

@vdahiya12 PR conflicts with 202411 branch

[mssonicbld]

@vdahiya12 PR conflicts with 202411 branch

[mssonicbld]

Cherry-pick PR to msft-202405: Azure/sonic-mgmt.msft#170