chore: stabilize Makefile, removed outdated tooling and upgrade versions

[pratik50]

What i changed

• Stabilized Makefile VERSION fallback for tagless clones (just for dev purpose [will update this parallely])
• Pinned golangci-lint version and updated config to v2 format
• Removed unused tooling installs (stringer/staticcheck standalone)
  this comes buid-in with latest version of go-lint
• Updated Go version/toolchain for consistent builds

Test

• Tested using the make file commands and working as expected in dev environment.

[github-actions]

CLA Assistant Lite bot All contributors have signed the CLA ✍️ ✅

[pratik50]

I have read the CLA Document and I hereby sign the CLA

[Copilot]

Pull request overview

This PR updates the project’s build/dev tooling to be more deterministic (Makefile + CI), upgrades the Go/toolchain baseline, and modernizes linting configuration while making a few small code/test cleanups.

Changes:

• Stabilize Makefile versioning for tagless clones and pin golangci-lint.
• Upgrade Go version/toolchain and update CI/go deps checks accordingly.
• Migrate .golangci.yml to the golangci-lint v2 config format and adjust enabled linters/formatters.

Reviewed changes

Copilot reviewed 9 out of 10 changed files in this pull request and generated 4 comments.

Show a summary per file

File	Description
Makefile	Adds VERSION fallback and pins golangci-lint install/version.
.golangci.yml	Migrates to v2 config structure; enables staticcheck and formatters.
go.mod	Updates Go/toolchain directives; promotes k8s.io/api to direct dependency.
buildscripts/checkdeps.sh	Raises minimum Go version check.
.github/workflows/build.yaml	Updates setup-go action, Go version, and pins gofumpt version.
pkg/helm/helm.go	Uses client.LocateChart for chart resolution in Apply/Upgrade.
pkg/installer/installer.go	Refactors store selection to a switch for secret manifest generation.
pkg/model/role/role.go	Simplifies stream validation logic.
pkg/iterator/iterator_test.go	Simplifies time equality assertions.
.gitignore	Ignores CLAUDE.md.

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[Copilot]

applyParseableSecret can call applyManifest with an empty secretManifest when store has an unexpected value (no default case). Returning an explicit error in a default branch would prevent applying an empty/invalid manifest and make failures clearer to users.

Suggested change

	secretManifest = getParseableSecretGcs(ps, objectStoreConfig)
	secretManifest = getParseableSecretGcs(ps, objectStoreConfig)
	default:
	return fmt.Errorf("unsupported object store: %v", store)

[Copilot]

The curl | sh pipeline can succeed even if curl fails (because the shell returns the status of the last command in the pipeline). This can lead to silently missing golangci-lint installs. Consider avoiding the pipeline (download then execute), or ensure pipefail is enabled so failures propagate; also consider pinning the install script to a specific tag/commit instead of master to reduce supply-chain risk.

Suggested change

	@curl -sSfL https://raw.githubusercontent.com/golangci/golangci-lint/master/install.sh | sh -s -- -b $(GOPATH)/bin $(GOLANGCI_LINT_VERSION)
	@tmpfile=$$(mktemp); trap 'rm -f "$$tmpfile"' EXIT; \
	curl -sSfL https://raw.githubusercontent.com/golangci/golangci-lint/$(GOLANGCI_LINT_VERSION)/install.sh -o "$$tmpfile" && \
	sh "$$tmpfile" -b $(GOPATH)/bin $(GOLANGCI_LINT_VERSION)