Add semantic error test for assignment to literal #7741

Job	Run time
LPython CI (3.10, macos-latest)	5m 29s
LPython CI (3.10, ubuntu-latest)	10m 31s
Build LPython to WASM	7m 21s
LPython CI (3.10, windows-2025)	17m 21s
Upload Tarball	52s
Test PIP Installable Packages	2m 59s
Build Jupyter Kernel	4m 13s
Test CPython Interop (@pythoncall)	3m 3s
Check Debug build	3m 34s
Check Release build	7m 16s
Run Integration tests with Python 3.9	3m 20s
Run Integration tests with Python 3.11	3m 23s
Run SymPy tests	3m 48s
Run Integration tests with Python 3.10	3m 17s
Test LLVM 10	3m 44s
Run Integration tests with Python 3.12	3m 25s
Test LLVM 16	3m 34s
Test LLVM 15	3m 46s
	1h 30m 56s

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