chore(internal): allow the build script to be run without yarn instal…

…led (#173)

build

@@ -3,7 +3,12 @@ set -exuo pipefail
 
 node scripts/check-version.cjs
 
-yarn tsc
+RUNNER="yarn"
+if ! command -v yarn &> /dev/null; then
+  RUNNER="npx"
+fi
+
+$RUNNER tsc
 
 # Build into dist and will publish the package from there,
 # so that src/resources/foo.ts becomes <package root>/resources/foo.js
@@ -23,10 +28,10 @@ done
 node scripts/make-dist-package-json.cjs > dist/package.json
 
 # build to .js/.mjs/.d.ts files
-tsc-multi
+$RUNNER tsc-multi
 # copy over handwritten .js/.mjs/.d.ts files
 cp src/_shims/*.{d.ts,js,mjs} dist/_shims
-tsc-alias -p tsconfig.build.json
+$RUNNER tsc-alias -p tsconfig.build.json
 # we need to add exports = module.exports = Modern Treasury Node to index.js;
 # No way to get that from index.ts because it would cause compile errors
 # when building .mjs
@@ -46,7 +51,7 @@ else
   find dist -type f -exec sed -i "${REFERENCE_SUBS}" {} +
 fi
 
-yarn prettier --loglevel=warn --write .
+$RUNNER prettier --loglevel=warn --write .
 
 # make sure that nothing crashes when we require the output CJS or
 # import the output ESM