[sqlserver] mark pyodbc as a windows dependency
[sqlserver] mark pyodbc as a windows dependency

We're going to stop using Omnibus for these pip dependencies, so they
all have to be listed in the requirements files.
Let's do this for the SQLServer check dependencies.

DataDog/integrations-core,serverdensity/sd-agent-core-plugins,itsuugo/integrations-core,StackVista/sts-agent-integrations-core,s-maj/integrations-core,serverdensity/sd-agent-core-plugins,itsuugo/integrations-core,itsuugo/integrations-core,StackVista/sts-agent-integrations-core,serverdensity/sd-agent-core-plugins,serverdensity/sd-agent-core-plugins,s-maj/integrations-core,DataDog/integrations-core,varlib1/servermall,StackVista/sts-agent-integrations-core,DataDog/integrations-core,StackVista/sts-agent-integrations-core,varlib1/servermall,varlib1/servermall,varlib1/servermall,StackVista/sts-agent-integrations-core,itsuugo/integrations-core,DataDog/integrations-core,serverdensity/sd-agent-core-plugins,DataDog/integrations-core,DataDog/integrations-core,s-maj/integrations-core,DataDog/integrations-core,DataDog/integrations-core,DataDog/integrations-core,s-maj/integrations-core,varlib1/servermall,s-maj/integrations-core,itsuugo/integrations-core,DataDog/integrations-core