Fix null value deprecation error for Str::endsWith

[LeoColomb]

This is almost nothing but is hitting me hard right now.
When the bundle values are missing (which can happen for different reasons), then the local value gets null which is not accepted as an argument for Str::endsWith().

ErrorException: Deprecated: str_ends_with(): Passing null to parameter #1 ($haystack) of type string is deprecated
#44 root/vendor/illuminate/support/Str.php(322): Illuminate\Support\Str::endsWith
#43 root/vendor/log1x/sage-svg/src/SageSvg.php(96): Log1x\SageSvg\SageSvg::asset
#42 root/vendor/log1x/sage-svg/src/SageSvg.php(69): Log1x\SageSvg\SageSvg::getContents
#41 root/vendor/log1x/sage-svg/src/SageSvg.php(49): Log1x\SageSvg\SageSvg::render
#40 root/vendor/log1x/sage-svg/src/helpers.php(16): get_svg
#39 root/web/app/themes/theme/storage/framework/views/246666fbe147d06bbcf009f62287874f.php(8): require