fix(build): Invalid commit hash in docker image

[ankitpokhrel]

The commit hash is determined using this command during the build process. This is fine and works well. However, the docker image built in the CI has invalid git commit hash.

$ jira version
(Version="1.2.0", GitCommit="9d8a0afd75b68aa519367f93c240429117cc4090", CommitDate="2022-12-16T10:53:08+00:00", GoVersion="go1.18.3", Compiler="gc", Platform="darwin/amd64")

$ docker run -it --rm ghcr.io/ankitpokhrel/jira-cli:latest
~ # jira version
(Version="v1.2.0", GitCommit="4ae631faa92d59052320464d09e0f34842c5f971", CommitDate="2022-12-17T10:21:57+00:00", GoVersion="go1.17.11", Compiler="gc", Platform="linux/amd64")

$ git show 4ae631faa92d59052320464d09e0f34842c5f971
fatal: bad object 4ae631faa92d59052320464d09e0f34842c5f971

This happens because we are ignoring .github directory in .dockerignore. This results in creation of stash ref with a different hash each time we create a build in a CI.

This PR fixes the above mentioned issue.