kiro cli breaks gitfarm authentication on AL2

### Checks

- [x] I have searched [github.com/aws/amazon-q-developer-cli/issues](https://github.com/aws/amazon-q-developer-cli/issues?q=) and there are no duplicates of my issue
- [x] I have run `q doctor` in the affected terminal session
- [x] I have run `q restart` and replicated the issue again

### Operating system

Linux 5.10.244-220.970.amzn2int.x86_64 - Amazon Linux 2

### Expected behaviour

git pull --rebase works after authentication (Amazon Linux 2 cloud desktop)

### Actual behaviour

dev-dsk-alleyuan-2b-2b28c754 % git pull --rebase
/home/alleyuan/.local/share/kiro-cli/ssh_inner: line 15: Bad configuration option: setenv
/home/alleyuan/.local/share/kiro-cli/ssh_inner: terminating, 1 bad configuration options
fatal: Could not read from remote repository.

Please make sure you have the correct access rights
and the repository exists.

### Steps to reproduce

install kiro CLI with SSH integration on an AL2 cloud desktop with openSSH 7.4 (non upgradable)

authenticate and attempt to pull from gitfarm

### Environment

```yaml

[q-details]
version = "1.21.0"
hash = "dc54efd85f411d6b4347d192733ff40650d38dfb"
date = "2025-11-26T22:31:51.735818Z (5d ago)"
variant = "minimal"

[system-info]
chip = "AMD EPYC 7R13 Processor"
total-cores = 16
memory = "61.53 GB"

[system-info.os.linux]
kernel_version = "5.10.244-220.970.amzn2int.x86_64"
id = "amzn"
name = "Amazon Linux"
pretty_name = "Amazon Linux 2"
version_id = "2"
version = "2"
variant = "internal"

[environment]
cwd = "/workplace/USER/fesinfra/src/AmazonBedrockConstructs"
cli-path = "/workplace/USER/fesinfra/src/AmazonBedrockConstructs"
os = "Linux"
shell-path = "/usr/bin/zsh"
shell-version = "5.8"
install-method = "toolbox"
in-ssh = true

[env-vars]
PATH = "/home/USER/.pyenv/shims:/usr/lib/jvm/java-17-amazon-corretto.x86_64/bin:/home/USER/.asdf/shims:/home/USER/.asdf/bin:/home/USER/.local/bin:/home/USER/.toolbox/bin:/home/USER/.pyenv/bin:/usr/lib/jvm/java-17-amazon-corretto.x86_64/bin:/home/USER/.nvm/versions/node/v14.21.1/bin:/home/USER/.local/bin:/home/USER/.toolbox/bin:/home/linuxbrew/.linuxbrew/bin:/home/linuxbrew/.linuxbrew/sbin:/usr/local/bin:/usr/bin:/home/USER/bin:/usr/local/sbin:/usr/sbin:/home/USER/.local/bin:/home/USER/bin"
QTERM_SESSION_ID = "b941cd908f49488a9672be4c167541b7"
Q_PARENT = "/tmp/kiro-cli-parent-c594d52726664541bcb2876481ca213a.socket"
Q_SET_PARENT_CHECK = "1"
Q_TERM = "1.21.0"
SHELL = "/bin/zsh"
TERM = "xterm-256color"
```