Fix Psalm code scanning alerts
Fix Psalm code scanning alerts

InvalidScalarArgument (apps/theming/lib/IconBuilder.php#L213): https://github.com/nextcloud/server/security/code-scanning/6691
InvalidScalarArgument (apps/theming/lib/IconBuilder.php#L213): https://github.com/nextcloud/server/security/code-scanning/6692
MissingReturnType (apps/theming/lib/IconBuilder.php#L226): https://github.com/nextcloud/server/security/code-scanning/6693
MissingParamType (apps/theming/lib/IconBuilder.php#L226): https://github.com/nextcloud/server/security/code-scanning/6694
MissingParamType (apps/theming/lib/IconBuilder.php#L226): https://github.com/nextcloud/server/security/code-scanning/6695
PossiblyFalseArgument (apps/theming/lib/IconBuilder.php#L232): https://github.com/nextcloud/server/security/code-scanning/6696

Signed-off-by: MichaIng <5f726662e7ca541c0aec63efdec81c7c2711727a@dietpi.com>

nextcloud/server,nextcloud/server,nextcloud/server,nextcloud/server