ci: upgrade golangci-lint to v2.12.2 for Go 1.25 support

The previous golangci-lint v1.62.2 was built with Go 1.23 and fails on
the go 1.25.0 directive required by betterleaks. Migrate .golangci.yml
to the v2 config format (dead linters dropped by the migration tool),
keep gating parity by disabling linters introduced after v1.62 and
restricting staticcheck to SA checks, and fix the one new prealloc
finding.

Author: Ubisoft-potato

.github/workflows/main.yml

@@ -25,9 +25,9 @@ jobs:
           go install gotest.tools/gotestsum@latest
 
       - name: Install golangci-lint
-        uses: golangci/golangci-lint-action@971e284b6050e8a5849b72094c50ab08da042db8 # v6.1.1
+        uses: golangci/golangci-lint-action@ba0d7d2ec06a0ea1cb5fa41b2e4a3ab91d21278a # v9.3.0
         with:
-          version: v1.62.2
+          version: v2.12.2
 
   github-actions-docs:
     runs-on: ubuntu-latest

.golangci.yml

@@ -1,64 +1,82 @@
-project_name: ld-find-code-refs
-
+version: "2"
 run:
-  deadline: 120s
   tests: false
-
 linters:
-  enable-all: true
+  default: all
   disable:
-      - golint
-      - stylecheck
-      - gochecknoglobals
-      - lll
-      - errcheck
-      - interfacer
-      - tagliatelle
-      - varnamelen
-      - nonamedreturns
-      - nlreturn # re-enable this after fixing all cases
-      - gomnd # re-enable this after fixing all cases
-      - nosnakecase
-      - ifshort # re-enable
-      - nilerr #re-enable
-      - goerr113
-      - exhaustivestruct
-      - exhaustruct
-      - exhaustive
-      - godot
-      - wsl #fix
-      - gocognit
-      - revive
-      - errname
-      - cyclop
-      - gofumpt # fix
-      - gci
-      - nestif # fix
-      - gosec
-      - gocritic
-      - depguard
-      - tagalign
-      - nilnil
-  fast: false
-
-linter-settings:
-  goimports:
-    local-prefixes: github.com/launchdarkly,gopkg.in/launchdarkly
-
+    - cyclop
+    - funcorder
+    - godoclint
+    - gomodguard
+    - modernize
+    - noinlineerr
+    - wsl_v5
+    - depguard
+    - err113
+    - errcheck
+    - errname
+    - exhaustive
+    - exhaustruct
+    - gochecknoglobals
+    - gocognit
+    - gocritic
+    - godot
+    - gosec
+    - lll
+    - mnd
+    - nestif
+    - nilerr
+    - nilnil
+    - nlreturn
+    - nonamedreturns
+    - revive
+    - tagalign
+    - tagliatelle
+    - varnamelen
+    - wsl
+  settings:
+    staticcheck:
+      checks:
+        - all
+        - -ST*
+        - -QF*
+  exclusions:
+    generated: lax
+    rules:
+      - linters:
+          - staticcheck
+        text: SA5011
+      - path: (.+)\.go$
+        text: error returned from external package is unwrapped
+      - path: (.+)\.go$
+        text: error returned from interface method should be wrapped
+      - path: (.+)\.go$
+        text: comparing with == will fail on wrapped errors. Use errors.Is to check for a specific error
+      - path: (.+)\.go$
+        text: comparing with != will fail on wrapped errors. Use errors.Is to check for a specific error
+      - path: (.+)\.go$
+        text: non-wrapping format verb for fmt.Errorf. Use `%w` to format errors
+      - path: (.+)\.go$
+        text: append to slice `projectKeys` with non-zero initialized length
+    paths:
+      - third_party$
+      - builtin$
+      - examples$
 issues:
-  exclude:
-    - "error returned from external package is unwrapped"
-    - "error returned from interface method should be wrapped"
-    - "comparing with == will fail on wrapped errors. Use errors.Is to check for a specific error" # should fix
-    - "comparing with != will fail on wrapped errors. Use errors.Is to check for a specific error" # should fix
-    - "non-wrapping format verb for fmt.Errorf. Use `%w` to format errors" # should fix
-    - "append to slice `projectKeys` with non-zero initialized length"
-  exclude-rules:
-    # Exclude some `staticcheck` messages.
-    - linters:
-        - staticcheck
-      text: "SA5011" # fix
-
-  exclude-use-default: false
+  max-issues-per-linter: 1000
   max-same-issues: 1000
-  max-per-linter: 1000
+formatters:
+  enable:
+    - gofmt
+    - goimports
+  settings:
+    goimports:
+      local-prefixes:
+        - github.com/launchdarkly
+        - gopkg.in/launchdarkly
+  exclusions:
+    generated: lax
+    paths:
+      - third_party$
+      - builtin$
+      - examples$

search/delimiters.go

@@ -8,9 +8,9 @@ import (
 // Get a list of delimiters to use for flag key matching
 // If defaults are disabled, only additional configured delimiters will be used
 func GetDelimiters(opts options.Options) []string {
-	delims := []string{`"`, `'`, "`"}
-	if opts.Delimiters.DisableDefaults {
-		delims = []string{}
+	delims := make([]string, 0, 3+len(opts.Delimiters.Additional)) //nolint:mnd
+	if !opts.Delimiters.DisableDefaults {
+		delims = append(delims, `"`, `'`, "`")
 	}
 
 	delims = append(delims, opts.Delimiters.Additional...)