CI: build staticcheck release from source

Upstream's latest version works fine when built with Go 1.22,
but their release archives are built with 1.21,
and that seems to trigger a panic due to issue
dominikh/go-tools#1496.

Thankfully, building from source is easy enough.
It shouldn't cause any noticeable slowdown, since we reuse both
the modules and build Go caches via actions/setup-go.

.github/workflows/main.yml

@@ -60,10 +60,12 @@ jobs:
           curl -L https://github.com/dominikh/go-tools/releases/download/2023.1.6/staticcheck_linux_amd64.tar.gz | tar -xzf -
       - name: Run staticcheck
         run: |
-          ./staticcheck/staticcheck ./... 2> staticcheck/stderr
+          go install honnef.co/go/tools/cmd/[email protected]
+          staticcheck -debug.version
+          staticcheck ./... 2> staticcheck-stderr
       - name: Check staticcheck stderr (this step isn't needed because we are using actions/setup-go@v5 on GitHub hosted runner)
         run: |
-          if cat staticcheck/stderr | grep "matched no packages" ; then
+          if cat staticcheck-stderr | grep "matched no packages" ; then
             echo "staticcheck step did nothing, due to https://github.com/vocdoni/vocdoni-node/issues/444"
             echo "Please re-run job."
             # seize the opportunity to fix the underlying problem: a permissions error in ~/.cache