[v10.3.x] chore: bump Go to 1.21.8 (#83936)

chore: bump Go to 1.21.8 (#83927)

* chore: bump Go to 1.21.8

Signed-off-by: Dave Henderson <dave.henderson@grafana.com>

* bump workflows too

Signed-off-by: Dave Henderson <dave.henderson@grafana.com>

---------

Signed-off-by: Dave Henderson <dave.henderson@grafana.com>
(cherry picked from commit 01fb2cff62)

.github/workflows/pr-codeql-analysis-go.yml

@@ -26,7 +26,7 @@ jobs:
     - name: Set go version
       uses: actions/setup-go@v4
       with:
-        go-version: '1.21.6'
+        go-version: '1.21.8'
 
     # Initializes the CodeQL tools for scanning.
     - name: Initialize CodeQL