Add staticcheck.conf to reduce unactionable noise in IDEs (#34036)

Since we already specify a list of staticcheck rules to ignore in the
scripts/staticcheck.sh wrapper script, this hoists those preferences up to the
top of the package tree, so they also affect the staticcheck integration in
editors like VSCode. This avoids unnecessary yellow-squiggles for capitalized
error messages, and makes integrated linting much more useful.

Author: nfagerlund

Diff for: scripts/staticcheck.sh

@@ -13,9 +13,6 @@ skip=$skip"|internal/planproto|internal/tfplugin5|internal/tfplugin6"
 
 packages=$(go list ./... | egrep -v ${skip})
 
-# We are skipping style-related checks, since terraform intentionally breaks
-# some of these. The goal here is to find issues that reduce code clarity, or
-# may result in bugs. We also disable fucntion deprecation checks (SA1019)
-# because our policy is to update deprecated calls locally while making other
-# nearby changes, rather than to make cross-cutting changes to update them all.
-go run honnef.co/go/tools/cmd/staticcheck -checks 'all,-SA1019,-ST*' ${packages}
+# Note that we globally disable some checks. The list is controlled by the
+# top-level staticcheck.conf file in this repo.
+go run honnef.co/go/tools/cmd/staticcheck ${packages}

Diff for: staticcheck.conf

@@ -0,0 +1,7 @@
+# Our goal in using staticcheck is to find issues that reduce code clarity, or
+# may result in bugs. We are skipping style-related checks, since terraform
+# intentionally breaks some of these. We also disable function deprecation
+# checks (SA1019) because our policy is to update deprecated calls locally while
+# making other nearby changes, rather than to make cross-cutting changes to
+# update them all.
+checks = ["all", "-SA1019", "-ST*"]