cmd/tailscale: don't depend on regexp in minbox builds

Updates #12614
Updates #18562

Change-Id: Ife4f10c55d1d68569938ffd68ffe72eef889e200
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>

cmd/tailscaled/depaware-minbox.txt

@@ -420,8 +420,6 @@ tailscale.com/cmd/tailscaled dependencies: (generated by github.com/tailscale/de
         path                                                         from io/fs+
         path/filepath                                                from crypto/x509+
         reflect                                                      from crypto/x509+
-        regexp                                                       from tailscale.com/cmd/tailscale/cli
-        regexp/syntax                                                from regexp
         runtime                                                      from crypto/internal/fips140+
         runtime/debug                                                from github.com/klauspost/compress/zstd+
         slices                                                       from crypto/tls+

cmd/tailscaled/deps_test.go

@@ -294,6 +294,7 @@ func TestMinTailscaledWithCLI(t *testing.T) {
 			"tailscale.com/clientupdate/distsign":    "unexpected distsign dep",
 			"archive/tar":                            "unexpected archive/tar dep",
 			"tailscale.com/feature/conn25":           "unexpected conn25 dep",
+			"regexp":                                 "unexpected regexp dep; bloats binary",
 		},
 	}.Check(t)
 }