Set-GitHubRepository: Add Support for 'Secret Scanning' Option (#391)

Adds the `SecretScanning` parameter to the `Set-GitHubRepository` function.

> The parameter was implemented using the `Enabled, Disabled` parameter validate set rather than a switch to mirror the pattern used by the GitHub API.

Fixes #390

#### References

- https://docs.github.com/en/rest/repos/repos#update-a-repository

Author: X-Guardian

GitHubRepositories.ps1

@@ -1049,6 +1049,9 @@ filter Set-GitHubRepository
     .PARAMETER DefaultBranch
         Update the default branch for this repository.
 
+    .PARAMETER SecretScanning
+        Specifies whether to enable or disable secret scanning for the repository.
+
     .PARAMETER Private
         Specify this to make the repository private.
         To change a repository to be public, specify -Private:$false
@@ -1177,6 +1180,9 @@ filter Set-GitHubRepository
 
         [string] $DefaultBranch,
 
+        [ValidateSet('Enabled', 'Disabled')]
+        [string] $SecretScanning,
+
         [switch] $Private,
 
         [switch] $NoIssues,
@@ -1251,6 +1257,14 @@ filter Set-GitHubRepository
     if ($PSBoundParameters.ContainsKey('WebCommitSignoffRequired')) { $hashBody['web_commit_signoff_required'] = $WebCommitSignoffRequired.ToBool() }
     if ($PSBoundParameters.ContainsKey('Archived')) { $hashBody['archived'] = $Archived.ToBool() }
 
+    $securityAndAnalysis = @{}
+    if ($PSBoundParameters.ContainsKey('SecretScanning')) {
+        $securityAndAnalysis['secret_scanning'] = @{ 'status' = $SecretScanning.ToLower()}
+    }
+    if ($securityAndAnalysis.Count -ne 0) {
+        $hashBody['security_and_analysis'] = $securityAndAnalysis
+    }
+
     if ($Force -and (-not $Confirm))
     {
         $ConfirmPreference = 'None'

Tests/GitHubRepositories.tests.ps1

@@ -723,6 +723,27 @@ Describe 'GitHubRepositories\Set-GitHubRepository' {
             $repo = New-GitHubRepository -RepositoryName $repoName
         }
 
+        Context -Name 'When updating a public repository with Secret Scanning' {
+            BeforeAll -ScriptBlock {
+                $updateGithubRepositoryParms = @{
+                    OwnerName = $repo.owner.login
+                    RepositoryName = $repoName
+                    SecretScanning = 'Enabled'
+                }
+
+                $updatedRepo = Set-GitHubRepository @updateGithubRepositoryParms -PassThru
+            }
+
+            It 'Should return an object of the correct type' {
+                $updatedRepo | Should -BeOfType PSCustomObject
+            }
+
+            It 'Should return the correct properties' {
+                $updatedRepo.name | Should -Be $repoName
+                $updatedRepo.security_and_analysis.secret_scanning.status | Should -Be 'enabled'
+            }
+        }
+
         Context -Name 'When updating a public repository with auto-merge set to true' {
             BeforeAll -ScriptBlock {
                 $updateGithubRepositoryParms = @{