PSUseOutputTypeCorrectly complains "... type is not declared in the OutputType attribute" even though it is

Steps to reproduce

PSScriptAnalyzer is complaining about a missing OutputType attribute, even though I did set it correctly.
See PSScriptAnalyzer CI comment under my commits: https://github.com/jantari/LSUClient/commit/a6c2fcc1622aa221d0be73debb4a97baea7b36b5

Easiest way to reproduce is test with my exact file:

mkdir test-pssa
curl.exe "https://raw.githubusercontent.com/jantari/LSUClient/develop/public/Install-LSUpdate.ps1" -o .\test-pssa\Install-LSUpdate.ps1
Import-Module PSScriptAnalyzer -RequiredVersion 1.20.0 # Latest
Invoke-ScriptAnalyzer -Path .\test-pssa -ExcludeRule PSAvoidTrailingWhitespace -Recurse -Verbose

Expected behavior

PSScriptAnalyzer should have no complaints.

Actual behavior

RuleName                            Severity     ScriptName Line  Message
--------                            --------     ---------- ----  -------
PSUseOutputTypeCorrectly            Information  Install-LS 93    The cmdlet 'Install-LSUpdate' returns an object of type
                                                 Update.ps1       'PackageInstallResult' but this type is not declared in the
                                                                  OutputType attribute.
PSUseOutputTypeCorrectly            Information  Install-LS 125   The cmdlet 'Install-LSUpdate' returns an object of type
                                                 Update.ps1       'PackageInstallResult' but this type is not declared in the
                                                                  OutputType attribute.

Environment data

Issue is reproducible under both:

> $PSVersionTable
Name                           Value
----                           -----
PSVersion                      7.2.1
PSEdition                      Core
GitCommitId                    7.2.1
OS                             Microsoft Windows 10.0.22538
Platform                       Win32NT
PSCompatibleVersions           {1.0, 2.0, 3.0, 4.0…}
PSRemotingProtocolVersion      2.3
SerializationVersion           1.1.0.1
WSManStackVersion              3.0

> (Get-Module -ListAvailable PSScriptAnalyzer).Version | ForEach-Object { $_.ToString() }
1.20.0
1.19.1

and:

> $PSVersionTable
Name                           Value
----                           -----
PSVersion                      5.1.22538.1000
PSEdition                      Desktop
PSCompatibleVersions           {1.0, 2.0, 3.0, 4.0...}
BuildVersion                   10.0.22538.1000
CLRVersion                     4.0.30319.42000
WSManStackVersion              3.0
PSRemotingProtocolVersion      2.3
SerializationVersion           1.1.0.1

> (Get-Module -ListAvailable PSScriptAnalyzer).Version | ForEach-Object { $_.ToString() }
1.19.0
1.20.0
1.19.1

Start by reproducing the report with Install-LSUpdate.ps1 from the linked reproduction and Invoke-ScriptAnalyzer using PSScriptAnalyzer 1.20.0. Investigate the PSUseOutputTypeCorrectly rule and compare its inferred PackageInstallResult output with the declared OutputType; done means the false-positive diagnostics at lines 93 and 125 no longer appear while valid warnings remain detected.