chore: upgrade Go, golangci-lint and CI deps (#5)

Upgrade main development to use Go 1.23, while still running CI against 1.20 and later.

Also update golangci-lint to v2.

.golangci.yml

@@ -1,29 +1,10 @@
-linters-settings:
-  funlen:
-    lines: 100
-    statements: 150
-  goconst:
-    min-occurrences: 5
-    ignore-strings: "^ format $"
-  gocyclo:
-    min-complexity: 20
-  golint:
-    min-confidence: 0
-  govet:
-    check-shadowing: true
-    enable-all: true
-    disable:
-      - fieldalignment
-  lll:
-    line-length: 80
-    tab-width: 4
-  maligned:
-    suggest-new: true
-  misspell:
-    locale: US
-
+---
+version: "2"
+run:
+  modules-download-mode: readonly
+  allow-parallel-runners: true
 linters:
-  disable-all: true
+  default: none
   enable:
     - asciicheck
     - bodyclose
@@ -31,18 +12,14 @@ linters:
     - errcheck
     - errorlint
     - exhaustive
-    - exportloopref
     - funlen
     - gochecknoinits
     - goconst
     - gocritic
     - gocyclo
     - godot
-    - gofumpt
-    - goimports
     - goprintffuncname
     - gosec
-    - gosimple
     - govet
     - importas
     - ineffassign
@@ -60,33 +37,63 @@ linters:
     - sqlclosecheck
     - staticcheck
     - tparallel
-    - typecheck
     - unconvert
     - unparam
     - unused
     - wastedassign
     - whitespace
-
-issues:
-  exclude-rules:
-    - path: "_test\\.go"
-      linters:
-        - funlen
-        - dupl
-    - source: "^//go:generate "
-      linters:
-        - lll
-    - source: "`json:"
-      linters:
-        - lll
-    - source: "`xml:"
-      linters:
-        - lll
-    - source: "`yaml:"
-      linters:
-        - lll
-
-run:
-  timeout: 2m
-  allow-parallel-runners: true
-  modules-download-mode: readonly
+  settings:
+    funlen:
+      lines: 100
+      statements: 150
+    goconst:
+      min-occurrences: 5
+    gocyclo:
+      min-complexity: 20
+    govet:
+      disable:
+        - fieldalignment
+      enable-all: true
+    lll:
+      line-length: 80
+      tab-width: 4
+    misspell:
+      locale: US
+  exclusions:
+    generated: lax
+    presets:
+      - comments
+      - common-false-positives
+      - legacy
+      - std-error-handling
+    rules:
+      - linters:
+          - dupl
+          - funlen
+        path: _test\.go
+      - linters:
+          - lll
+        source: "^//go:generate "
+      - linters:
+          - lll
+        source: "`json:"
+      - linters:
+          - lll
+        source: "`xml:"
+      - linters:
+          - lll
+        source: "`yaml:"
+    paths:
+      - third_party$
+      - builtin$
+      - examples$
+formatters:
+  enable:
+    - gofumpt
+    - goimports
+  exclusions:
+    generated: lax
+    paths:
+      - third_party$
+      - builtin$
+      - examples$