Fix hard coded absolute paths in a number of files

[mithro]

A number of the files in #8 have absolute paths which should be relative (to environment variables or similar).

Examples;

• skywater-pdk-libs-sky130_bag3_pr/workspace_setup/cds.lib.core

  Lines 34 to 35 in e53df63

  	DEFINE scs8hd /tools/commercial/skywater/swtech130/skywater-src-nda/scs8hd/V0.0.2/oa/scs8hd
  	DEFINE scs8hd_dv /tools/commercial/skywater/swtech130/skywater-src-nda/scs8hd/V0.0.2/oa/scs8hd_dv

• skywater-pdk-libs-sky130_bag3_pr/workspace_setup/.bashrc

  Lines 76 to 79 in e53df63

  	# Enable devtoolset
  	source /opt/rh/devtoolset-8/enable
  	source /opt/rh/rh-git29/enable
  	source /opt/rh/httpd24/enable

• skywater-pdk-libs-sky130_bag3_pr/calibre_setup/lvs_adc.runset

  Lines 21 to 26 in e53df63

  	*lvsRunDir: $BAG_WORK_DIR/calibre_run/lvs/AAA_SAR_lay/AAA_Slice
  	*lvsLayoutPaths: /tools/B/felicia_guo/bag3-sky130-2/calibre_run/lvs/AAA_SAR_lay/AAA_Slice/layout.gds
  	*lvsLayoutPrimary: AAA_Slice
  	*lvsLayoutLibrary: AAA_SAR_lay
  	*lvsLayoutView: layout
  	*lvsSourcePath: /tools/B/felicia_guo/bag3-sky130-2/gen_outputs/bag_sar/AAA_Slice.cdl

The command grep -R '\s/[^/ ]' * should help you find them...