chore!: remove helpers package

[geyslan]

Close: #264
Close: #387
Close: #407

commit 15a44de

chore: update test matrices

commit 7697ddf

chore: specify a minimum go version for selftest

commit 176c311

chore!: remove helpers package

Conclusion of #458

This also creates KernelSymbolToAddr in selftest common package.

[geyslan]

@oshaked1 @OriGlassman please signal us when your end is ready for removal.

[Copilot]

Pull Request Overview

This PR removes the deprecated helpers package from libbpfgo and migrates dependencies to use the environment package from Tracee. This is a breaking change that eliminates the internal helpers module while updating selftests to use external dependencies.

• Removes the entire helpers package and all its functionality
• Migrates selftest dependencies from the helpers package to Tracee's environment package
• Updates CI configuration to support Go 1.21+ due to Tracee's toolchain requirements

Reviewed Changes

Copilot reviewed 33 out of 40 changed files in this pull request and generated no comments.

Show a summary per file

File	Description
helpers/*	Complete removal of the deprecated helpers package and all its files
selftest/*/go.mod	Updates module dependencies to use Tracee's environment package instead of helpers
selftest/*/main.go	Changes import statements from helpers to Tracee's environment package
.github/workflows/pr.yaml	Removes helpers unit tests and updates Go version matrix to 1.21+
Makefile	Removes helpers test targets and references
docs/helpers.md	Removes documentation for the deprecated helpers package
Readme.md	Updates documentation to remove helpers-related make targets

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[yanivagman]

LGTM