fix: Upgrade to latest version of graphql-codegen cli (#479)

## Summary

From Brad Bunce

> We're seeing 13 high-severity npm audit findings when using
[@launchdarkly](https://launchdarkly.slack.com/team/UKEE4GBS6)/observability-node@1.1.0.
They all trace back to lodash@4.17.21 pulled in through the
@graphql-codegen/cli dependency chain:
> 
>
[@launchdarkly](https://launchdarkly.slack.com/team/UKEE4GBS6)/observability-node
>   → @graphql-codegen/cli
>     → @graphql-codegen/plugin-helpers
>       → lodash <=4.17.23
> The specific lodash advisories are:
> 
> GHSA-r5fr-rjxr-66jc — Code injection via _.template
> GHSA-f23m-r3pf-42rh — Prototype pollution via _.unset / _.omit
> GHSA-xxjr-mmjv-4gpg — Prototype pollution in _.unset / _.omit
> npm audit fix can't resolve these without downgrading
[@launchdarkly](https://launchdarkly.slack.com/team/UKEE4GBS6)/observability-node
to 0.1.0, which is a breaking change. The only consumer-side workaround
is an overrides entry to force a patched lodash version, which carries
compatibility risk.
> 
> Could the @graphql-codegen dependencies in the observability-node
package be updated to versions that no longer depend on vulnerable
lodash? Appreciate any timeline or workaround guidance you can share.

The latest version of graphql-codegen cli removed lodash as an
unnecessary dependency.

## How did you test this change?

Ran codegen of observability-node successfully

<!-- CURSOR_SUMMARY -->
---

> [!NOTE]
> **Low Risk**
> Low risk because changes are confined to dev/build tooling
(`graphql-codegen`) and lockfile updates, with no production runtime
code modifications.
> 
> **Overview**
> Upgrades `@graphql-codegen/cli` from `^5.0.7` to `^6.3.1` for both
`@launchdarkly/observability-node` and
`@launchdarkly/observability-shared`, and moves it out of
`observability-node` runtime `dependencies` into `devDependencies`.
> 
> Regenerates `yarn.lock` to reflect the new codegen dependency tree
(notably updating related `@graphql-codegen/*`, `@graphql-tools/*`, and
`@babel/*` packages).
> 
> <sup>Reviewed by [Cursor Bugbot](https://cursor.com/bugbot) for commit
425f432. Bugbot is set up for automated
code reviews on this repo. Configure
[here](https://www.cursor.com/dashboard/bugbot).</sup>
<!-- /CURSOR_SUMMARY -->

Author: JustinRatner

sdk/@launchdarkly/observability-node/package.json

@@ -29,7 +29,6 @@
 		"access": "public"
 	},
 	"dependencies": {
-		"@graphql-codegen/cli": "^5.0.7",
 		"@launchdarkly/node-server-sdk-otel": "^1.3.0",
 		"@prisma/instrumentation": ">=5.0.0",
 		"require-in-the-middle": "^7.4.0"
@@ -39,6 +38,7 @@
 		"@launchdarkly/node-server-sdk": "^9.9.2"
 	},
 	"devDependencies": {
+		"@graphql-codegen/cli": "^6.3.1",
 		"@launchdarkly/js-server-sdk-common": "^2.15.2",
 		"@launchdarkly/node-server-sdk": "^9.9.2",
 		"@opentelemetry/api": "^1.9.0",

sdk/@launchdarkly/observability-shared/package.json

@@ -13,7 +13,7 @@
 		"test": "vitest run"
 	},
 	"devDependencies": {
-		"@graphql-codegen/cli": "^5.0.7",
+		"@graphql-codegen/cli": "^6.3.1",
 		"typescript": "^5.8.3",
 		"vitest": "^3.2.4"
 	},