[updatecli][shell] Bump version to 1.21 (#188)

* chore: Updated the content of the file "/tmp/updatecli/github/elastic...

... /elastic-agent-libs/.golangci.yml"

Made with ❤️️ by updatecli

* chore: Updated the content of the file "/tmp/updatecli/github/elastic...

... /elastic-agent-libs/.go-version"

Made with ❤️️ by updatecli

---------

Co-authored-by: apmmachine <apmmachine@users.noreply.github.com>

.go-version

@@ -1 +1 @@
-1.21.7
+1.21.8

.golangci.yml

@@ -83,7 +83,7 @@ linters-settings:
 
   gosimple:
     # Select the Go version to target. The default is '1.13'.
-    go: "1.21.7"
+    go: "1.21.8"
 
   nakedret:
     # make an issue if func has more lines of code than this setting and it has naked returns; default is 30
@@ -117,19 +117,19 @@ linters-settings:
 
   staticcheck:
     # Select the Go version to target. The default is '1.13'.
-    go: "1.21.7"
+    go: "1.21.8"
     # https://staticcheck.io/docs/options#checks
     checks: ["all"]
 
   stylecheck:
     # Select the Go version to target. The default is '1.13'.
-    go: "1.21.7"
+    go: "1.21.8"
     # https://staticcheck.io/docs/options#checks
     checks: ["all"]
 
   unused:
     # Select the Go version to target. The default is '1.13'.
-    go: "1.21.7"
+    go: "1.21.8"
 
   gosec:
     excludes: