fix: Fix issue when creating PR to update homebrew formula

[hnrkndrssn]

There was an issue with how the body was being passed to GitHub

InvalidOperation: Response status code does not indicate success: 400 (Bad Request). 
September 30th 2022 14:20:47Error
At /home/Octopus/Work/20220930042032-4232676-7759/Script.ps1:47 char:5 
September 30th 2022 14:20:47Error
+     Invoke-RestMethod -Method POST ` 
September 30th 2022 14:20:47Error
+     ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 
September 30th 2022 14:20:47Error
at <ScriptBlock>, /home/Octopus/Work/20220930042032-4232676-7759/Script.ps1: line 47 
September 30th 2022 14:20:47Error
at <ScriptBlock>, <No file>: line 1 
September 30th 2022 14:20:47Error
at <ScriptBlock>, /home/Octopus/Work/20220930042032-4232676-7759/Octopus.FunctionAppenderContext.ps1: line 211 
September 30th 2022 14:20:47Error
at <ScriptBlock>, /home/Octopus/Work/20220930042032-4232676-7759/Bootstrap.Octopus.FunctionAppenderContext.ps1: line 1708 
September 30th 2022 14:20:47Error
at <ScriptBlock>, <No file>: line 1 
September 30th 2022 14:20:47Error
at <ScriptBlock>, <No file>: line 1 
September 30th 2022 14:20:47Error
{"message":"Problems parsing JSON","documentation_url":"https://docs.github.com/rest/reference/pulls#create-a-pull-request"}