fix(security/unknown/godeltaprof): update go toolchain directive to v1.26.6 [security]

| datasource     | package | from    | to     |
| -------------- | ------- | ------- | ------ |
| golang-version | go      | 1.25.12 | 1.26.6 |


Signed-off-by: renovate-sh-app[bot] <219655108+renovate-sh-app[bot]@users.noreply.github.com>
Signed-off-by: renovate-sh-app[bot] <219655108+renovate-sh-app[bot]@users.noreply.github.com>

Author: renovate-sh-app[bot]

godeltaprof/go.mod

@@ -2,6 +2,6 @@ module github.com/grafana/pyroscope-go/godeltaprof
 
 go 1.25.0
 
-toolchain go1.25.12
+toolchain go1.26.6
 
 require github.com/klauspost/compress v1.18.7