refactor: modernize Go API usage and error handling in core utilities (3/5)

[bstoll]

This is part 3/5 of an overall cleanup effort to fix golangci-lint violations and format files across the repository. In this step:

• Replace deprecated k8s.io/utils/pointer with k8s.io/utils/ptr across api, events, and pods packages.
• Handle ignored return values and standardize error capitalization in core utilities (exec, flags, logshim, metrics).
• Update experimental extensions and helpers under x/.

[coveralls]

Coverage Report for CI Build 29054969593

Coverage decreased (-0.04%) to 42.014%

Details

• Coverage decreased (-0.04%) from the base build.
• Patch coverage: 24 uncovered changes across 7 files (16 of 40 lines covered, 40.0%).
• No coverage regressions found.

Uncovered Changes

File	Changed	Covered	%
x/wire/file/client/main.go	4	0	0.0%
x/wire/forward/main.go	4	0	0.0%
x/wire/intf/client/main.go	4	0	0.0%
x/wire/wire.go	4	0	0.0%
flags/flags.go	3	0	0.0%
x/webhook/main.go	3	0	0.0%
api/metallb/clientset/v1beta1/client.go	5	3	60.0%
Total (11 files)	40	16	40.0%

Coverage Regressions

No coverage regressions found.

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Coverage Stats

Relevant Lines:	12341
Covered Lines:	5185
Line Coverage:	42.01%
Coverage Strength:	0.48 hits per line

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💛 - Coveralls