Fix libyaml github URL and name for libyaml file

[traylenator]

The github path was incorrect and the 0.2.5 was being included twice resulting in:

Attempting to fetch from canonical URL "https://github.com/yaml/libyaml/releases/download/libyaml/yaml-0.2.5-0.2.5.tar.gz"
An error was encountered evaluating block. Retrying..

Will only be seen with - VANAGON_USE_MIRRORS=false

[puppetlabs-jenkins]

Can one of the admins verify this patch?

[CLAassistant]

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[traylenator]

CLA signed between CERN IT and Puppetlabs.

[joshcooper]

$ bx rake vanagon:component_diff -- -p el-7-x86_64 --from upstream/master --to HEAD 
...
Here is what your code changes would affect:

Project agent-runtime-main

Platform name: el-7-x86_64
    Component 'libyaml'
        Field: url
        --------------------
        - https://github.com/yaml/libyaml/releases/download/libyaml/yaml-0.2.5-0.2.5.tar.gz
        + https://github.com/yaml/libyaml/releases/download/0.2.5/yaml-0.2.5.tar.gz

where

$ curl -sLI https://github.com/yaml/libyaml/releases/download/libyaml/yaml-0.2.5-0.2.5.tar.gz | grep HTTP/
HTTP/2 404
$ curl -sLI https://github.com/yaml/libyaml/releases/download/0.2.5/yaml-0.2.5.tar.gz | grep HTTP/
HTTP/2 302 
HTTP/2 200