[ogormans-deptstack]

Description of your changes

Sprig's first, last, rest, and initial call reflect.TypeOf(list).Kind()
without guarding against an untyped nil. When a template reaches for a field that
isn't populated yet — e.g. a status that a composed resource hasn't reported — list
is an untyped nil, reflect.TypeOf(nil) is nil, and .Kind() panics with an
invalid memory address. text/template surfaces that as error calling first: ...
and the whole reconcile fails.

This replaces those four accessors in GetNewTemplateWithFunctionMaps with thin
wrappers (nilSafeList) that treat a nil input as an empty result and otherwise
defer to Sprig's must* variants, which report unsupported types as errors instead
of panics . It follows the existing env/expandenv removal pattern already in
that function. Valid inputs behave exactly as before.

Credit to @shashankvarma499, who traced this root cause in the issue thread — the
approach here follows their write-up. Happy to hand this off to him if he'd rather carry it
himself, or if this issue is stale or considered not necessary to fix yet.

I ran into something similar writing compositions against Crossplane CRDs (I maintain
kubectl-schemagen, a lesser used krew plugin that scaffolds manifests for CRDs including
Crossplane's Composition / CompositeResourceDefinition / EnvironmentConfig), where
referencing a not-yet-populated status field is easy to do by accident.

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Fixes #78

I have:

• [ x] Read and followed Crossplane's [contribution process].
• [ x] Added or updated unit tests for my change.