fix: invalid type for pool reset

[ldez]

The pool uses []goconst.Issue, but a *[]goconst.Issue is used to reset the buffer.

=== RUN   Test_IssuePool
--- FAIL: Test_IssuePool (0.00s)
panic: interface conversion: interface {} is *[]goconst.Issue, not []goconst.Issue [recovered]
	panic: interface conversion: interface {} is *[]goconst.Issue, not []goconst.Issue

goroutine 6 [running]:
testing.tRunner.func1.2({0x62ca60, 0xc0000a2a50})
	/home/ldez/.gvm/gos/go1.23.8/src/testing/testing.go:1632 +0x230
testing.tRunner.func1()
	/home/ldez/.gvm/gos/go1.23.8/src/testing/testing.go:1635 +0x35e
panic({0x62ca60?, 0xc0000a2a50?})
	/home/ldez/.gvm/gos/go1.23.8/src/runtime/panic.go:791 +0x132
github.com/jgautheron/goconst.GetIssueBuffer(...)
	/home/ldez/sources/golangci-lint-linters/goconst/api.go:33
github.com/jgautheron/goconst.Test_IssuePool(0xc0000a8820?)
	/home/ldez/sources/golangci-lint-linters/goconst/api_test.go:568 +0x48
testing.tRunner(0xc0000a8820, 0x67cbe8)
	/home/ldez/.gvm/gos/go1.23.8/src/testing/testing.go:1690 +0xf4
created by testing.(*T).Run in goroutine 1
	/home/ldez/.gvm/gos/go1.23.8/src/testing/testing.go:1743 +0x390

Related to b210ef1

[ldez]

Note: I think the IssuesPool can be removed.
I'm not sure about the real impact of the pool because it's not really used, and global variables are never friendly for something that can be used as a library.

[codecov]

Codecov Report

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Additional details and impacted files

@@            Coverage Diff            @@
##             master      #37   +/-   ##
=========================================
  Coverage          ?   66.01%           
=========================================
  Files             ?        4           
  Lines             ?     1030           
  Branches          ?        0           
=========================================
  Hits              ?      680           
  Misses            ?      316           
  Partials          ?       34           

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[jgautheron]

@ldez I was running some tests there but will clean this up