fix: Use SystemTime instead of Instant everywhere #13517

Job	Run time
cargo deny	28s
Lint Rust	1m 52s
Check provider database	5s
Rust doc comments	27s
Rust tests (ubuntu-latest, 1.75.0)	2m 44s
Rust tests (windows-latest, 1.75.0)	8m 27s
Build C library (ubuntu-latest)	2m 39s
Build C library (macos-latest)	11m 33s
Rust tests (macos-latest, 1.75.0)	4m 39s
Rust tests (ubuntu-latest, 1.70.0)	3m 4s
Python lint	16s
Build deltachat-rpc-server (ubuntu-latest)	2m 8s
Build deltachat-rpc-server (macos-latest)	5m 0s
Build deltachat-rpc-server (windows-latest)	5m 57s
JSON-RPC Python tests (ubuntu-latest, 3.12)	1m 40s
JSON-RPC Python tests (macos-latest, 3.12)	2m 28s
JSON-RPC Python tests (windows-latest, 3.12)	2m 27s
JSON-RPC Python tests (ubuntu-latest, pypy3.10)	2m 46s
JSON-RPC Python tests (macos-latest, pypy3.10)	2m 53s
JSON-RPC Python tests (ubuntu-latest, 3.7)	2m 0s
CFFI Python tests (ubuntu-latest, 3.12)	6m 53s
CFFI Python tests (macos-latest, 3.12)	8m 44s
CFFI Python tests (ubuntu-latest, pypy3.10)	7m 42s
CFFI Python tests (macos-latest, pypy3.10)	6m 8s
CFFI Python tests (ubuntu-latest, 3.7)	5m 4s
	1h 38m 4s

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