refactor: refactor tests to replace RIBP references with APB4 equivalents

- Updated test files to change instances of ribp_if to apb4_if in various test cases, ensuring consistency with the new APB4 interface.
- Modified assertions and checks in tests to reflect the new APB4 naming conventions, including changes in expected output and input files.
- Adjusted the test descriptions to accurately represent the APB4 functionality being tested, particularly in timer, UART, and GPIO tests.
- Ensured that all relevant paths and file names in the tests are updated to point to the new APB4 implementations, maintaining the integrity of the test suite.

tests/test_sta_constraints.py

@@ -52,7 +52,7 @@ def test_core_sdc_covers_current_clock_domains(tmp_path: Path) -> None:
     assert "get_pins -quiet" in sdc
     assert "get_ports -quiet" in sdc
     assert "set clk_jtag_port [require_ports \"clock jtag\" {jtag_tck_i_pad}]" in sdc
-    assert "u_retrosoc.u_ip_ribp_wrapper.u_axi4_dvp.u_dvp_pclk_clk_buf/clk_o" in sdc
+    assert "u_retrosoc.u_apb4_periph.u_axi4_dvp.u_dvp_pclk_clk_buf/clk_o" in sdc
     assert "-group [get_clocks {clk_external clk_system}]" in sdc
     assert "set_clock_transition 0.1 [get_clocks {clk_dvp}]" in sdc
     assert "set_input_transition" not in sdc