chore: update golangci.yml

[tenthirtyam]

Description

• Removes the use of the following linters: 'deadcode' and 'varcheck'. Each are deprecated as of golangci-lint v1.49.0. The owners seem to have abandoned these linters and they are replaced by unused.
• Updates deprecated configurations and removes redundant or default settings.
• Removed fast: true under linters since it's not necessary when disable-all is used and specific linters are explicitly enabled.
• Removed max-issues-per-linter and max-same-issues under issues to simplify the configuration, assuming default values are acceptable. If specific limits are needed, these can be added back with specific values.
• Consolidated exclude-functions syntax for clarity.

Before:

packer-plugin-vmware on chore/update-golangci
➜ golangci-lint run
WARN [config_reader] The configuration option `run.skip-files` is deprecated, please use `issues.exclude-files`. 
WARN [config_reader] The configuration option `output.format` is deprecated, please use `output.formats` 
WARN [config_reader] The configuration option `linters.errcheck.ignore` is deprecated, please use `linters.errcheck.exclude-functions`. 
WARN The linter 'deadcode' is deprecated (since v1.49.0) due to: The owner seems to have abandoned the linter. Replaced by unused. 
WARN The linter 'varcheck' is deprecated (since v1.49.0) due to: The owner seems to have abandoned the linter. Replaced by unused. 
ERRO [linters_context] deadcode: This linter is fully inactivated: it will not produce any reports. 
ERRO [linters_context] varcheck: This linter is fully inactivated: it will not produce any reports. 

After:

packer-plugin-vmware on chore/update-golangci
➜ golangci-lint run

packer-plugin-vmware on chore/update-golangci

[nywilken]

👍🏽