Add argument `t` to `source_terms`

[codecov[bot]]

Codecov Report

All modified and coverable lines are covered by tests :white_check_mark:

Project coverage is 69.37%. Comparing base (c01d9ad) to head (2f0daf1).

Additional details and impacted files

```diff @@ Coverage Diff @@ ## main #582 +/- ## ========================================== + Coverage 69.35% 69.37% +0.01% ========================================== Files 76 76 Lines 4621 4620 -1 ========================================== Hits 3205 3205 + Misses 1416 1415 -1 ``` | [Flag](https://app.codecov.io/gh/trixi-framework/TrixiParticles.jl/pull/582/flags?src=pr&el=flags&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=trixi-framework) | Coverage Δ | | |---|---|---| | [unit](https://app.codecov.io/gh/trixi-framework/TrixiParticles.jl/pull/582/flags?src=pr&el=flag&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=trixi-framework) | `69.37% <100.00%> (+0.01%)` | :arrow_up: | Flags with carried forward coverage won't be shown. [Click here](https://docs.codecov.io/docs/carryforward-flags?utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=trixi-framework#carryforward-flags-in-the-pull-request-comment) to find out more.

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