dependency_support: Bump cocotb

Bump Cocotb to the version supporting specifying timescale and dumping
waveforms using Icarus Verilog.

Internal-tag: [#46586]
Signed-off-by: Robert Winkler <rwinkler@antmicro.com>

Author: rw1nkler

dependency_support/pip_requirements.txt

@@ -2,5 +2,6 @@ dataclasses-json==0.5.7
 jwt==1.3.1
 requests==2.28.2
 absl-py==1.4.0
-cocotb==1.8.0
 klayout==0.28.8
+
+git+https://github.com/cocotb/cocotb.git@a853db95b0019db6796a6803aa94304bde743e4e