Remove Redundant Specification of CMake Source Directory

[threeal]

This issue addresses a redundant behavior observed during the configuration of a CMake project. Currently, if the source directory is not explicitly specified, it defaults to . (the current directory). However, specifying the current directory as the source directory is unnecessary since CMake inherently processes the current directory as the source directory by default. To streamline the process, it is proposed to specify the source directory in the CMake configuration arguments only when the user explicitly specifies the source-dir input.