chore(ci): replace SourceKnight with setup-sp

[Rushaway]

Summary

Replaces the SourceKnight-based build (maxime1907/action-sourceknight) with a native GitHub Actions workflow using rumblefrog/setup-sp, matching the pattern already rolled out to other srcdslab repos (e.g. sm-plugin-AdminRoom).

Plugin targets

Target	Source file
CountryTags	addons/sourcemod/scripting/CountryTags.sp

Dependencies (from sourceknight.yaml)

Name	Repo	Unpack source -> dest (as declared in sourceknight.yaml)
multicolors	https://github.com/srcdslab/sm-plugin-MultiColors	/addons/sourcemod/scripting/include -> /addons/sourcemod/scripting/include

(The sourcemod dependency was type: tar — the SourceMod runtime itself — and is now provided by rumblefrog/setup-sp at version 1.12.x instead of a downloaded tarball.)

Packaging

The old workflow copied .sourceknight/package/* plus the full csgo/ directory (which contains csgo/addons/sourcemod/configs/countryflags.cfg and csgo/materials/panorama/... flag images) into the release artifact. The new workflow replicates this by copying the compiled .smx into addons/sourcemod/plugins/ and copying the contents of csgo/ into the package root, preserving the existing configs and materials.

Not locally validated

Per instructions, this migration was done without cloning dependency repos, downloading spcomp, or compiling anything locally. This PR relies on the CI run itself to confirm the build compiles successfully — no local spcomp run was performed.

Manual verification needed

• Confirm the CI build succeeds and the MultiColors include path used in the workflow (addons/sourcemod/scripting/include) matches what sm-plugin-MultiColors actually publishes.
• Confirm the packaged artifact (smx + csgo/ configs + materials) matches expectations of downstream consumers of the release archive.

🤖 Generated with Claude Code

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