Updated references to reflect changes made to the conb_1 cells in
a number of sky130 standard cell libraries to work around a
SkyWater DRC issue.

VERSION

diff --git a/VERSION b/VERSION
index bbecded..4535257 100644
--- a/VERSION
+++ b/VERSION
@@ -1 +1 @@
-1.0.530
+1.0.531

gf180mcu/gf180mcu.json

diff --git a/gf180mcu/gf180mcu.json b/gf180mcu/gf180mcu.json
index c2f479f..edb098e 100644
--- a/gf180mcu/gf180mcu.json
+++ b/gf180mcu/gf180mcu.json
@@ -89,7 +89,7 @@
         "magic": "MAGIC_COMMIT"
     },
     "reference": {
-        "open_pdks": "3863076405b31ae66bfc895a8cfe791706de9905",
+        "open_pdks": "8afc8346a57fe1ab7934ba5a6056ea8b43078e71",
         "magic": "eb81da6c56ff200ba3d7ceab41cdba5fde32b513",
         "gf180mcu_pdk": "a897aa30369d3bcec87d9d50ce9b01f320f854ef",
         "gf180mcu_fd_pr": "faef89e8c1b392733c32820a7b12e3a3847cc18c",

sky130/sky130.json

diff --git a/sky130/sky130.json b/sky130/sky130.json
index 64771c2..0eff2f3 100644
--- a/sky130/sky130.json
+++ b/sky130/sky130.json
@@ -94,21 +94,21 @@
         "magic": "MAGIC_COMMIT"
     },
     "reference": {
-        "open_pdks": "3863076405b31ae66bfc895a8cfe791706de9905",
+        "open_pdks": "8afc8346a57fe1ab7934ba5a6056ea8b43078e71",
         "magic": "eb81da6c56ff200ba3d7ceab41cdba5fde32b513",
         "sky130_fd_pr": "1232782c1b9fab3aacda74d67ce7c92bf7da8105",
         "sky130_fd_io": "250b1ec4f69d70705359a1a0d25f8778046ff6b3",
-        "sky130_fd_sc_hs": "9a855e97aa75f8a14be7eadc365c28d50045d5fc",
-        "sky130_fd_sc_ms": "26d0047c0e2dbe28fe4950f171411f6e8b3d0564",
-        "sky130_fd_sc_ls": "8e7040bfc58a17386e3d900c0e3b9c9163545c4a",
+        "sky130_fd_sc_hs": "b9b2be651c4ca109240709b7e3a7a91613b2eb56",
+        "sky130_fd_sc_ms": "3b95b8068f09b0f6dec28ae8d13f22ce980972ae",
+        "sky130_fd_sc_ls": "dfbb5b4ae9d80bcec3f0aad1dd5a47a2400df010",
         "sky130_fd_sc_lp": "b93a1a75fa1b864872ebb0b078f6a2dd6e318d7c",
-        "sky130_fd_sc_hd": "892688b66a3d7fc2839dead7209015f93ad9a73d",
-        "sky130_fd_sc_hdll": "d48faa83ef2d8573d85384c4eb019ab78295db0b",
-        "sky130_fd_sc_hvl": "5f544a6d5b9385ac563811e7a455b050eea5fb70",
+        "sky130_fd_sc_hd": "aed07ad6d4eff1861cb9d10f102d247231e3645c",
+        "sky130_fd_sc_hdll": "f67521458137f30a01ec76aad3028e77581446ae",
+        "sky130_fd_sc_hvl": "e5413e01fa071029ba84d9faa98d9acd80e75a38",
         "sky130_osu_sc_t12": "ac90ef0c622a9377a16b5218d9da3ac4169eeaaf",
         "sky130_osu_sc_t15": "95d1c19abb47e1b2945847acb4e817b1b8417c43",
         "sky130_osu_sc_t18": "aa2b509f3c8f32ea94fdb55ac9768754667c1658",
-        "sky130_sram_macros": "5ad1c96053ee8223fe7e956e314646adfce605dd",
+        "sky130_sram_macros": "c1e25c953f9502aed940810ce4b00bda000c69bb",
         "sky130_fd_bd_sram": "be33adbcf188fdeab5c061699847d9d440f7a084",
         "sky130_fd_pr_reram": "d6d2a3c6960aac0a0b12fc21221c31777bbf284d",
         "sky130_ml_xx_hd": "6eb3b0718552b034f1bf1870285ff135e3fb2dcb",