Rotate codecov keys for cake-contrib

[nils-a]

Background

Due to a security breach at codecov we're rotating the codecov keys.

Related: https://cake-build.slack.com/archives/C03B4CZ12/p1618492212087100 and https://cake-build.slack.com/archives/C03B4CZ10/p1618539830046400

cake-build

cake-build org has not granted access to codecov, so there's nothing to do for cake-build.

cake-contrib

Announcement in https://cake-contrib.slack.com/archives/C4PTD6RJ8/p1618565736012800

• [x] Cake.7zip
• [x] Cake.AliaSql
• [x] cake.asciidoctorj
• [x] Cake.Board
• [x] Cake.Bower
• [x] Cake.Chocolatey.Module
• [x] Cake.CodeAnalysisReporting
• [x] Cake.Codecov
• [x] CakeContrib.Guidelines
• [x] Cake.Coveralls
• [x] Cake.DocFx
• [x] Cake.DotNetTool.Module
• [x] Cake.DotNetVersionDetector
• [x] Cake.Email
• [x] Cake.Email.Common
• [x] Cake.Ember
• [x] Cake.EntityFramework
• [x] Cake.Fastlane
• [x] Cake.Figlet
• [x] Cake.FileHelpers
• [x] Cake.Ftp
• [x] Cake.Gem
• [x] Cake.Gradle
• [x] Cake.Graph
• [x] Cake.Grunt
• [x] Cake.Gulp
• [x] Cake.Hg
• [x] Cake.HgVersion
• [x] Cake.HockeyApp
• [x] Cake.Homebrew
• [x] Cake.Http
• [x] Cake.Incubator
• [x] Cake.Issues
• [x] Cake.Issues.DocFx
• [x] Cake.Issues.EsLint
• [x] Cake.Issues.InspectCode
• [x] Cake.Issues.Markdownlint
• [x] Cake.Issues.MsBuild
• [x] Cake.Issues.PullRequests
• [x] Cake.Issues.PullRequests.AppVeyor
• [x] Cake.Issues.PullRequests.AzureDevOps
• [x] Cake.Issues.PullRequests.GitHubActions
• [x] Cake.Issues.Reporting
• [x] Cake.Issues.Reporting.Generic
• [x] Cake.Issues.Reporting.Sarif
• [x] Cake.Issues.Sarif
• [x] Cake.Issues.Terraform
• [x] Cake.Json
• [x] Cake.Karma
• [x] Cake.Markdown-Pdf
• [x] Cake.MobileCenter
• [x] Cake.MsDeploy
• [x] Cake.Netlify
• [x] Cake.Npm
• [x] Cake.Npm.Module
• [x] Cake.Paket
• [x] Cake.Plist
• [x] Cake.Prca
• [x] Cake.Prca.Issues.DocFx
• [x] Cake.Prca.Issues.EsLint
• [x] Cake.Prca.Issues.InspectCode
• [x] Cake.Prca.Issues.Markdownlint
• [x] Cake.Prca.Issues.MsBuild
• [x] Cake.Prca.PullRequests.Tfs
• [x] Cake.ProtobufTools
• [x] Cake.Recipe.Tests
• [x] Cake.ReSharperReports
• [x] Cake.SemVer
• [x] Cake.SendGrid
• [x] Cake.SqlPackage
• [x] Cake.Squirrel
• [x] Cake.SSRS
• [x] Cake.StrongNameSigner
• [x] Cake.Svn
• [x] Cake.T4
• [x] Cake.Terraform
• [x] Cake.Tfx
• [x] Cake.Transifex
• [x] Cake.Twitter
• [x] Cake.Unity
• [x] Cake.UrlLoadDirective.Module
• [x] Cake.VsCode
• [x] Cake.VsMetrics
• [x] Cake.Warp
• [x] Cake.Webpack
• [x] Cake.WindowsAppStore
• [x] Cake.Xamarin
• [x] Cake.Yaml
• [x] Cake.Yeoman