[FEAT] Reduce binary size

[Equationzhao]

g v0.3.0 takes up 16.7 MiB, it is insane even given that it's statically compiled with -s -w flags.

Comparison with other Go-based apps:

$ g -1 --size
 3.8 MiB age.exe
 9.4 MiB dnscrypt-proxy.exe
11.8 MiB doggo.exe
 6.7 MiB f2.exe
 3.0 MiB goawk.exe

Originally posted by @sergeevabc in https://github.com/Equationzhao/g/discussions/172#discussioncomment-13082275

[Equationzhao]

The go size analyzer shows that go-get adds about 770 KB to the binary. Since go-git doesn't offer better performance compared to the git CLI, it's reasonable to remove this dependency.

• [x] remove go-git

[Equationzhao]

The go size analyzer shows that go-get adds about 770 KB to the binary. Since go-git doesn't offer better performance compared to the git CLI, it's reasonable to remove this dependency.

• [x] remove go-git

Compared to the original version with go-git, removing the dependency reduces the binary size by 3.2 MiB on macOS arm64.

[Equationzhao]

after using upx

[Equationzhao]

The go size analyzer shows that go-get adds about 770 KB to the binary. Since go-git doesn't offer better performance compared to the git CLI, it's reasonable to remove this dependency.

• [x] remove go-git

done in #240

[sergeevabc]

I try not to use UPX with programs that require frequent calls, and g is one of those. Why? Because the compressed file starts with a noticeable, and therefore annoying, half-second delay. There must be a way to reduce the size of the exe file by using other people's libraries more precisely and economically.

[Equationzhao]

The Windows x64 binary is now dropped to 8.8MB. There may still be room for further optimization, and I’ll keep an eye on this issue going forward.