function mockGithubOIDCResponse(aud= "https://github.com/hashicorp/vault-action") {
    const alg = 'RS256';
    const header = { alg: alg, typ: 'JWT' };
    const now = rsasign.KJUR.jws.IntDate.getNow();
    const payload = {
        jti: "unique-id",
        sub: "repo:hashicorp/vault-action:ref:refs/heads/main",
        aud,
        ref: "refs/heads/main",
        sha: "commit-sha",
        repository: "hashicorp/vault-action",
        repository_owner: "hashicorp",
        run_id: "1",
        run_number: "1",
        run_attempt: "1",
        actor: "github-username",
        workflow: "Workflow Name",
        head_ref: "",
        base_ref: "",
        event_name: "push",
        ref_type: "branch",
        job_workflow_ref: "hashicorp/vault-action/.github/workflows/workflow.yml@refs/heads/main",
        iss: 'vault-action',
        iat: now,
        nbf: now,
        exp: now + 3600,
    };
    const decryptedKey = rsasign.KEYUTIL.getKey(privateRsaKey);
    return rsasign.KJUR.jws.JWS.sign(alg, JSON.stringify(header), JSON.stringify(payload), decryptedKey);
}
Returns Github OIDC response mock
@param {string} aud Audience claim
@returns {string}