[build] Add go mod tidy before go mod vendor for Go 1.24 compat

Go 1.24 (shipped in Debian Trixie) is stricter about module graph
consistency. Running `go mod vendor` without `go mod tidy` first
fails with module resolution errors when the go.mod was written
for an older Go version.

Add `go mod tidy` before `go mod vendor`. This is backward
compatible — on Go 1.21 (bookworm) it is a no-op.

Signed-off-by: Rustiqly <rustiqly@users.noreply.github.com>

Author: rustiqly

Makefile

@@ -36,6 +36,15 @@ $(GO_MOD):
 	$(GO) mod init github.com/Azure/sonic-mgmt-common
 
 $(GO_DEPS): $(GO_MOD) $(GO_PATCHES)
+	@# Run go mod tidy only if installed Go >= go.mod's go directive
+	@GO_MOD_VER=$$(sed -n 's/^go //p' go.mod) && \
+	 GO_CUR_VER=$$($(GO) env GOVERSION | sed 's/go//') && \
+	 if printf '%s\n' "$$GO_MOD_VER" "$$GO_CUR_VER" | sort -V | head -1 | grep -qx "$$GO_MOD_VER"; then \
+	   echo "Running go mod tidy (Go $$GO_CUR_VER >= go.mod $$GO_MOD_VER)"; \
+	   $(GO) mod tidy; \
+	 else \
+	   echo "Skipping go mod tidy (Go $$GO_CUR_VER < go.mod $$GO_MOD_VER)"; \
+	 fi
 	$(GO) mod vendor
 	patches/apply.sh vendor
 	touch  $@