fix: golint installation for golang version above 1.26

[david-montano-circleci]

Description

Updated the Dockerfile.template to implement a conditional installation strategy for golangci-lint based on the Go version. For environments using Go 1.26 or higher, the linter is now compiled from source; older versions continue to use the binary installation script.
Fixes #374

Reasons

• Go 1.26 Compatibility: Building golangci-lint from source using go install for Go 1.26+ ensures the binary is perfectly linked with the container's specific toolchain, preventing potential execution issues with pre-compiled binaries on newer runtimes.
• Improved Logic: Refactored the version parsing into a MINOR_VER variable to make the shell conditional logic cleaner and more maintainable.
• Image Hygiene: Included a cleanup step to remove the temporary source directory (/tmp/golangci-lint-src) immediately after compilation to keep the image layer size optimized.

Checklist

Please check through the following before opening your PR. Thank you!

• I have made changes to the Dockerfile.template file only
• I have not made any manual changes to automatically generated files
• My PR follows best practices as described in the contributing guidelines
• (Optional, but recommended) My commits are signed