Rebuild Postgres caches weekly instead of daily (#9892)

The daily rebuilds are apparently creating too much of the cache load,
we're going over the GitHub limit of 10GB, and useful caches like the
libfuzzer examples start to get evicted.

I think weekly rebuilds also give a reasonable time frame to detect the
Postgres builds breaking due to environmen changes.

Author: akuzm

.github/workflows/libfuzzer.yaml

@@ -37,12 +37,12 @@ jobs:
       id: config
       run: python -B .github/gh_config_reader.py
 
-    # We are going to rebuild Postgres daily, so that it doesn't suddenly break
+    # We are going to rebuild Postgres weekly, so that it doesn't suddenly break
     # ages after the original problem.
     - name: Get date for build caching
       id: get-date
       run: |
-        echo "date=$(date +"%d")" >> $GITHUB_OUTPUT
+        echo "date=$(date +"%V")" >> $GITHUB_OUTPUT
 
     # we cache the build directory instead of the install directory here
     # because extension installation will write files to install directory

.github/workflows/linux-32bit-build-and-test.yaml

@@ -120,12 +120,12 @@ jobs:
     - name: Checkout TimescaleDB
       uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6.0.2
 
-    # We are going to rebuild Postgres daily, so that it doesn't suddenly break
+    # We are going to rebuild Postgres weekly, so that it doesn't suddenly break
     # ages after the original problem.
     - name: Get date for build caching
       id: get-date
       run: |
-        echo "date=$(date +"%d")" >> $GITHUB_OUTPUT
+        echo "date=$(date +"%V")" >> $GITHUB_OUTPUT
 
     # we cache the build directory instead of the install directory here
     # because extension installation will write files to install directory

.github/workflows/linux-build-and-test.yaml

@@ -110,12 +110,12 @@ jobs:
     - name: Checkout TimescaleDB
       uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6.0.2
 
-    # We are going to rebuild Postgres daily, so that it doesn't suddenly break
+    # We are going to rebuild Postgres weekly, so that it doesn't suddenly break
     # ages after the original problem.
     - name: Get date for build caching
       id: get-date
       run: |
-        echo "date=$(date +"%d")" >> $GITHUB_OUTPUT
+        echo "date=$(date +"%V")" >> $GITHUB_OUTPUT
 
     # on macOS the path used is depending on the runner version leading to cache failure
     # when the runner version changes so we extract runner version from path and add it

.github/workflows/llm-fuzzer.yaml

@@ -88,12 +88,12 @@ jobs:
       if: github.event_name == 'pull_request'
       run: git fetch origin ${{ github.event.pull_request.base.ref }} --depth=50
 
-    # We are going to rebuild Postgres daily, so that it doesn't suddenly break
+    # We are going to rebuild Postgres weekly, so that it doesn't suddenly break
     # ages after the original problem.
     - name: Get date for build caching
       id: get-date
       run: |
-        echo "date=$(date +"%d")" >> $GITHUB_OUTPUT
+        echo "date=$(date +"%V")" >> $GITHUB_OUTPUT
 
     # Create a directory for sanitizer logs. This directory is referenced by
     # ASAN_OPTIONS, LSAN_OPTIONS, and UBSAN_OPTIONS

.github/workflows/sanitizer-build-and-test.yaml

@@ -91,12 +91,12 @@ jobs:
     - name: Checkout TimescaleDB
       uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6.0.2
 
-    # We are going to rebuild Postgres daily, so that it doesn't suddenly break
+    # We are going to rebuild Postgres weekly, so that it doesn't suddenly break
     # ages after the original problem.
     - name: Get date for build caching
       id: get-date
       run: |
-        echo "date=$(date +"%d")" >> $GITHUB_OUTPUT
+        echo "date=$(date +"%V")" >> $GITHUB_OUTPUT
 
     # Create a directory for sanitizer logs. This directory is referenced by
     # ASAN_OPTIONS, LSAN_OPTIONS, and UBSAN_OPTIONS

.github/workflows/tests-fail-on-old-code.yaml

@@ -85,13 +85,13 @@ jobs:
         sudo apt-get update
         sudo apt-get install flex bison cmake
 
-    # We are going to rebuild Postgres daily, so that it doesn't suddenly break
+    # We are going to rebuild Postgres weekly, so that it doesn't suddenly break
     # ages after the original problem.
     - name: Get date for build caching
       if: steps.check.outputs.should_run == 'true'
       id: get-date
       run: |
-        echo "date=$(date +"%d")" >> $GITHUB_OUTPUT
+        echo "date=$(date +"%V")" >> $GITHUB_OUTPUT
 
     # we cache the build directory instead of the install directory here
     # because extension installation will write files to install directory

.github/workflows/windows-build-and-test.yaml

@@ -168,13 +168,13 @@ jobs:
     - name: Checkout TimescaleDB source
       uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6.0.2
 
-    # We are going to rebuild Postgres daily, so that it doesn't suddenly break
+    # We are going to rebuild Postgres weekly, so that it doesn't suddenly break
     # ages after the original problem.
     - name: Get date for build caching
       id: get-date
       shell: powershell
       run: |
-        echo "date=$(Get-Date -Format 'dd')" >> $env:GITHUB_OUTPUT
+        echo "date=$(Get-Date -UFormat '%V')" >> $env:GITHUB_OUTPUT
 
       # Use a cache for the PostgreSQL installation to speed things up
       # and avoid unnecessary package downloads. Since we only save