chore: update local golangci-lint installation

[alexandear]

Summary

Updates the installation script URL for golangci-lint in the script/lint.

Why

According to the official docs, installation commands are as follows:

# binary will be $(go env GOPATH)/bin/golangci-lint
curl -sSfL https://golangci-lint.run/install.sh | sh -s -- -b $(go env GOPATH)/bin v2.8.0

# or install it into ./bin/
curl -sSfL https://golangci-lint.run/install.sh | sh -s v2.8.0

# In Alpine Linux (as it does not come with curl by default)
wget -O- -nv https://golangci-lint.run/install.sh | sh -s v2.8.0

P.S. I'm one of the Golangci-lint developers.

What changed

• Changed the URL to install.sh in script/lint.
• Added explicit installation path (-b "$BINDIR").
• Added a newline to the EOF in script/lint for consistency.

MCP impact

• No tool or API changes
• Tool schema or behavior changed
• New tool added

Prompts tested (tool changes only)

• N/A

Security / limits

• No security or limits impact
• Auth / permissions considered
• Data exposure, filtering, or token/size limits considered

Tool renaming

• I am renaming tools as part of this PR (e.g. a part of a consolidation effort)
  • I have added the new tool aliases in deprecated_tool_aliases.go
• I am not renaming tools as part of this PR

Lint & tests

• Linted locally with ./script/lint
• Tested locally with ./script/test

Docs

• Not needed
• Updated (README / docs / examples)

[Copilot]

Pull request overview

Updates the local golangci-lint installation step used by this repo’s script/lint, aligning it with the official install URL and installing into the repository’s bin/ directory.

Changes:

• Switch golangci-lint installer URL to https://golangci-lint.run/install.sh.
• Install the binary into the repo-local bin/ directory via -b "$BINDIR".
• Add a trailing newline at EOF (diff noise around the final command line).