Fix MergeEnvVar panic (#4744) #4110

Job	Run time
cli / viam-cli	3m 54s
license_finder / Audit 3rd-Party Licenses	1m 15s
test / linux-amd64 Go Unit Tests	14m 11s
test / Test meta.json jsonschema	21s
test / linux-arm64 Go Unit Tests	15m 4s
test / Go 32-bit Unit Tests	10m 53s
test / Test Longer-running Motion Plans if affected / Check files	6s
test / Test Longer-running Motion Plans if affected / Motion Extended Tests	0s
test / All Tests Passing	1s
appimage / static 32-bit for appimage	5m 51s
appimage / AppImage Build (ubuntu-latest, ghcr.io/viamrobotics/rdk-devenv:amd64-cache, linux/amd64, amd64)	3m 13s
appimage / AppImage Build (ubuntu-small-arm, ghcr.io/viamrobotics/rdk-devenv:arm64-cache, linux/arm64, arm64)	4m 33s
droid / droid-build	0s
full-static / full-static	3m 3s
staticbuild / Set Build Timestamp	1s
staticbuild / Antique Build (ubuntu-latest, ghcr.io/viamrobotics/antique2:amd64-cache, linux/amd64)	2m 53s
staticbuild / Antique Build (ubuntu-small-arm, ghcr.io/viamrobotics/antique2:arm64-cache, linux/arm64)	4m 37s
appimage / AppImage Test (ubuntu-latest)	15s
appimage / AppImage Test (ubuntu-small-arm)	1m 2s
appimage / AppImage Test (pi4)	23s
appimage / Output Summary	0s
appimage / AppImage Test (pi5)	11s
staticbuild / Static Test (ubuntu-latest)	6s
staticbuild / Static Test (ubuntu-small-arm)	7s
staticbuild / Output Summary	0s
staticbuild / Static Test (pi4)	8s
staticbuild / Static Test (pi5)	7s
appimage / appimage-32bit	32s
staticbuild / Static Deploy	23s
appimage / AppImage Deploy	30s
Post Workflow Status To Slack	0s
	1h 13m 40s

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