script: Enable SC2001 rule for Gitian scripts

contrib/gitian-descriptors/gitian-linux.yml

@@ -144,7 +144,8 @@ script: |
   CONFIG_SITE=${BASEPREFIX}/$(echo "${HOSTS}" | awk '{print $1;}')/share/config.site ./configure --prefix=/
   make dist
   SOURCEDIST=$(echo bitcoin-*.tar.gz)
-  DISTNAME=$(echo ${SOURCEDIST} | sed 's/.tar.*//')
+  DISTNAME=${SOURCEDIST/%.tar.gz}
+
   # Correct tar file order
   mkdir -p temp
   pushd temp

contrib/gitian-descriptors/gitian-osx.yml

@@ -107,7 +107,7 @@ script: |
   CONFIG_SITE=${BASEPREFIX}/$(echo "${HOSTS}" | awk '{print $1;}')/share/config.site ./configure --prefix=/
   make dist
   SOURCEDIST=$(echo bitcoin-*.tar.gz)
-  DISTNAME=$(echo ${SOURCEDIST} | sed 's/.tar.*//')
+  DISTNAME=${SOURCEDIST/%.tar.gz}
 
   # Correct tar file order
   mkdir -p temp

contrib/gitian-descriptors/gitian-win-signer.yml

@@ -37,6 +37,6 @@ script: |
   make
   find ${UNSIGNED_DIR} -name "*-unsigned.exe" | while read i; do
     INFILE="$(basename "${i}")"
-    OUTFILE="$(echo "${INFILE}" | sed s/-unsigned//)"
+    OUTFILE="${INFILE/%-unsigned}"
     ./osslsigncode attach-signature -in "${i}" -out "${OUTDIR}/${OUTFILE}" -sigin "${SIGDIR}/${INFILE}.pem"
   done

contrib/gitian-descriptors/gitian-win.yml

@@ -114,7 +114,8 @@ script: |
   CONFIG_SITE=${BASEPREFIX}/$(echo "${HOSTS}" | awk '{print $1;}')/share/config.site ./configure --prefix=/
   make dist
   SOURCEDIST=$(echo bitcoin-*.tar.gz)
-  DISTNAME=$(echo ${SOURCEDIST} | sed 's/.tar.*//')
+  DISTNAME=${SOURCEDIST/%.tar.gz}
+
   # Correct tar file order
   mkdir -p temp
   pushd temp

test/lint/lint-shell.sh

@@ -23,7 +23,6 @@ disabled=(
     SC2162 # read without -r will mangle backslashes.
 )
 disabled_gitian=(
-    SC2001 # See if you can use ${variable//search/replace} instead.
     SC2094 # Make sure not to read and write the same file in the same pipeline.
     SC2129 # Consider using { cmd1; cmd2; } >> file instead of individual redirects.
     SC2230 # which is non-standard. Use builtin 'command -v' instead.