CSPL-3692: Update golang version to 1.24.0

[rlieberman-splunk]

Description

This pull request updates the project to use Go version 1.23.1 across various files and configurations, and updates documentation to reflect the Go version change.

Key Changes

• Updated GO_VERSION in .env to 1.23.1.
• Changed base image in Dockerfile and Dockerfile.distroless to use golang:1.23.1. [1] [2]
• Updated the Makefile to download opm version 1.23.1.
• Updated the Go version requirement in README.md to 1.23.1.
• Updated go.mod to specify Go version 1.23.1.

Testing and Verification

All unit, smoke, and integration tests were run in the pipeline.

Related Issues

• https://splunk.atlassian.net/browse/CSPL-3692
• https://splunk.atlassian.net/browse/VULN-33037

PR Checklist

• Code changes adhere to the project's coding standards.
• Relevant unit and integration tests are included.
• Documentation has been updated accordingly.
• All tests pass locally.
• The PR description follows the project's guidelines.

[coveralls]

Pull Request Test Coverage Report for Build 14777528210

Details

• 1 of 5 (20.0%) changed or added relevant lines in 2 files are covered.
• 1 unchanged line in 1 file lost coverage.
• Overall coverage increased (+0.02%) to 86.641%

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Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
pkg/splunk/enterprise/upgrade.go	0	4	0.0%

Files with Coverage Reduction	New Missed Lines	%
pkg/splunk/enterprise/afwscheduler.go	1	92.96%

Totals
Change from base Build 14714583762:	0.02%
Covered Lines:	10546
Relevant Lines:	12172

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💛 - Coveralls

[rlieberman-splunk]

Will be completed in #1488