Fixed the sky130 Makefile, which recently accidentally got committed
with a recipe intended for the continuous models, which exist only
in a private repository.  The error prevents open_pdks from
building and installing libs.tech/ngspice/.
diff --git a/VERSION b/VERSION
index 7681bff..aeffd51 100644
--- a/VERSION
+++ b/VERSION
@@ -1 +1 @@
-1.0.314
+1.0.315
diff --git a/sky130/Makefile.in b/sky130/Makefile.in
index 6b6bebe..f509275 100644
--- a/sky130/Makefile.in
+++ b/sky130/Makefile.in
@@ -1151,65 +1151,6 @@
 	fi
 
 primitive-%:
-	# Install device models from custom files
-	${STAGE} -source ./custom -target ${STAGING_PATH}/${SKY130$*} \
-		-ngspice sky130_fd_pr/combined_models/* \
-		2>&1 | tee -a ${SKY130$*}_make.log
-	# Install device layouts from custom sources
-	${STAGE} -source ./custom -target ${STAGING_PATH}/${SKY130$*} \
-		-gds sky130_fd_pr/*.gds \
-			options=custom/scripts/gds_import_setup.tcl \
-		-library primitive sky130_fd_pr 2>&1 | tee -a ${SKY130$*}_make.log
-	# Install base device library from vendor files.
-	${STAGE} -source ${SKYWATER_LIBS_PATH} -target ${STAGING_PATH}/${SKY130$*} \
-		-gds %l/latest/cells/*/*.gds \
-			no-copy=custom/sky130_fd_pr/*.gds \
-			include=custom/sky130_fd_pr/*.gds \
-			compile-only \
-			options=custom/scripts/gds_import_setup.tcl \
-		-lef %l/latest/cells/*/*.magic.lef compile-only \
-		-spice %l/latest/cells/*/*.spice filter=custom/scripts/rename_cells.py \
-		-library primitive sky130_fd_pr 2>&1 | tee -a ${SKY130$*}_make.log
-
-	# Custom:  Patch the models to remove the substrate pin from the PNP
-	# device, which has no independent substrate pin (collector=substrate)
-	${PATCH} -p4 -f -d ${STAGING_PATH}/${SKY130$*}/libs.ref/${PR_SPICE} \
-		< custom/patches/sky130_fd_pr_3.patch \
-		2>&1 | tee -a ${SKY130$*}_make.log || true
-
-	# Fix up the PNP model file before running the next modification
-	head -15 ${STAGING_PATH}/${SKY130$*}/libs.ref/${PR_SPICE}/sky130_fd_pr__pnp_05v5_W3p40L3p40.model.spice > ${STAGING_PATH}/${SKY130$*}/libs.ref/${PR_SPICE}/temp
-	tail -39 ${STAGING_PATH}/${SKY130$*}/libs.ref/${PR_SPICE}/sky130_fd_pr__pnp_05v5_W3p40L3p40.model.spice >> ${STAGING_PATH}/${SKY130$*}/libs.ref/${PR_SPICE}/temp
-	mv ${STAGING_PATH}/${SKY130$*}/libs.ref/${PR_SPICE}/temp  ${STAGING_PATH}/${SKY130$*}/libs.ref/${PR_SPICE}/sky130_fd_pr__pnp_05v5_W3p40L3p40.model.spice
-	# Custom:  Parse the (commented out) statistics blocks and generate
-	# ngspice-compatible monte carlo parameters for mismatch and process
-	./custom/scripts/mismatch_params.py ${EF_FORMAT} -variant=${SKY130$*} \
-		2>&1 | tee -a ${SKY130$*}_make.log || true
-	./custom/scripts/process_params.py ${EF_FORMAT} -variant=${SKY130$*} \
-		2>&1 | tee -a ${SKY130$*}_make.log || true
-	# Custom:  Change vt to local_vt in one file for Xyce compatibilty
-	./custom/scripts/xyce_hack.py \
-		${STAGING_PATH}/${SKY130$*}/libs.ref/${PR_SPICE}/sky130_fd_pr__res_iso_pw.model.spice \
-		2>&1 | tee -a ${SKY130$*}_make.log || true
-	# Custom:  Remove ACM model parameters from BSIM3 devices
-	./custom/scripts/xyce_hack2.py \
-		${STAGING_PATH}/${SKY130$*}/libs.ref/${PR_SPICE}/sky130_fd_pr__special_nfet_pass.pm3.spice \
-		2>&1 | tee -a ${SKY130$*}_make.log || true
-	./custom/scripts/xyce_hack2.py \
-		${STAGING_PATH}/${SKY130$*}/libs.ref/${PR_SPICE}/sky130_fd_pr__special_pfet_pass.pm3.spice \
-		2>&1 | tee -a ${SKY130$*}_make.log || true
-	./custom/scripts/xyce_hack2.py \
-		${STAGING_PATH}/${SKY130$*}/libs.ref/${PR_SPICE}/sky130_fd_pr__special_nfet_latch.pm3.spice \
-		2>&1 | tee -a ${SKY130$*}_make.log || true
-
-	# Custom:  Add special device ID layers to bipolar layouts in magic
-	# to make the extraction models correct.
-	./custom/scripts/add_bipolar_ids.py ${EF_FORMAT} -variant=${SKY130$*} \
-		2>&1 | tee -a ${SKY130$*}_make.log || true
-
-primitive-legacy-%:
-	# This is the former recipe for primitive-% and has been superceded
-	# by the combined device models found in custom/sky130_fd_pr/.
 	# Install device subcircuits from vendor files
 	${STAGE} -source ${SKYWATER_LIBS_PATH} -target ${STAGING_PATH}/${SKY130$*} \
 		-ngspice sky130_fd_pr/latest/models/* \